Organic light-emitting device

ABSTRACT

An organic light-emitting device including a predetermined host and a thermally activated delayed fluorescence emitter.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims priority to and the benefit of Korean PatentApplication No. 10-2018-0112382, filed on Sep. 19, 2018, in the KoreanIntellectual Property Office, and all of the benefits accruing therefromunder 35 U.S.C. § 119, the disclosure of which is incorporated herein inits entirety by reference.

BACKGROUND 1. Field

One or more embodiments relate to an organic light-emitting device.

2. Description of the Related Art

Organic light-emitting devices are self-emission devices that producefull-color images, and also have wide viewing angles, high contrastratios, short response times, and excellent characteristics in terms ofbrightness, driving voltage, and response speed, compared to devices inthe art.

In an example, an organic light-emitting device includes an anode, acathode, and an organic layer that is disposed between the anode and thecathode and includes an emission layer. A hole transport region may bebetween the anode and the emission layer, and an electron transportregion may be between the emission layer and the cathode. Holes providedfrom the anode may move toward the emission layer through the holetransport region, and electrons provided from the cathode may movetoward the emission layer through the electron transport region.Carriers, such as holes and electrons, recombine in an emission layerregion to produce excitons. These excitons transit from an excited stateto a ground state, thereby generating light.

SUMMARY

Provided is an organic light-emitting device having a high efficiencyand a long lifespan.

Additional aspects will be set forth in part in the description whichfollows and, in part, will be apparent from the description, or may belearned by practice of the presented embodiments.

According to an aspect of an embodiment, an organic light-emittingdevice includes:

a first electrode;

a second electrode facing the first electrode; and

an emission layer disposed between the first electrode and the secondelectrode,

wherein the emission layer includes a host and a thermally activateddelayed fluorescence emitter, and the host includes a compoundrepresented by Formula 1, a compound represented by Formula 2, or acombination thereof:

In Formulae 1 and 2,

Z₁ to Z₆ may each independently be:

hydrogen, deuterium, —F, —Cl, —Br, —I, or a cyano group; or

a C₁-C₂₀ alkyl group, a phenyl group, a biphenyl group, a terphenylgroup, a dibenzofuranyl group, or a dibenzothiophenyl group, eachunsubstituted or substituted with deuterium, —F, —Cl, —Br, —I, a cyanogroup, a C₁-C₂₀ alkyl group, a phenyl group, a biphenyl group, or anycombination thereof,

b1 to b6 may each independently be 1, 2, 3, or 4, and

in Formulae 1 and 2, at least one of, i) Z₁ in the number of b1, ii) Z₂in the number of b2, iii) Z₃ in the number of b3, iv) Z₄ in the numberof b4, v) Z₅ in the number of b5, and vi) R₆ in the number of b6 may bea cyano group.

BRIEF DESCRIPTION OF THE DRAWINGS

These and/or other aspects will become apparent and more readilyappreciated from the following description of the embodiments, taken inconjunction with FIGURE which is a schematic view of an organiclight-emitting device according to an embodiment.

DETAILED DESCRIPTION

Reference will now be made in detail to embodiments, examples of whichare illustrated in the accompanying drawings, wherein like referencenumerals refer to like elements throughout. In this regard, the presentembodiments may have different forms and should not be construed asbeing limited to the descriptions set forth herein. Accordingly, theembodiments are merely described below, by referring to the figures, toexplain aspects. As used herein, the term “and/or” includes any and allcombinations of one or more of the associated listed items. Expressionssuch as “at least one of,” when preceding a list of elements, modify theentire list of elements and do not modify the individual elements of thelist.

It will be understood that when an element is referred to as being “on”another element, it can be directly on the other element or interveningelements may be present therebetween. In contrast, when an element isreferred to as being “directly on” another element, there are nointervening elements present there are no intervening elements present.

It will be understood that, although the terms “first,” “second,”“third” etc. may be used herein to describe various elements,components, regions, layers and/or sections, these elements, components,regions, layers and/or sections should not be limited by these terms.These terms are only used to distinguish one element, component, region,layer or section from another element, component, region, layer, orsection. Thus, “a first element,” “component,” “region,” “layer,” or“section” discussed below could be termed a second element, component,region, layer, or section without departing from the teachings herein.

The terminology used herein is for the purpose of describing particularembodiments only and is not intended to be limiting. As used herein,“a,” “an,” “the,” and “at least one” do not denote a limitation ofquantity, and are intended to cover both the singular and plural, unlessthe context clearly indicates otherwise. For example, “an element” hasthe same meaning as “at least one element,” unless the context clearlyindicates otherwise. It will be further understood that the terms“comprises” and/or “comprising,” or “includes” and/or “including” whenused in this specification, specify the presence of stated features,regions, integers, steps, operations, elements, and/or components, butdo not preclude the presence or addition of one or more other features,regions, integers, steps, operations, elements, components, and/orgroups thereof.

Furthermore, relative terms, such as “lower” or “bottom” and “upper” or“top,” may be used herein to describe one element's relationship toanother element as illustrated in the Figures. It will be understoodthat relative terms are intended to encompass different orientations ofthe device in addition to the orientation depicted in the Figures. Forexample, if the device in one of the figures is turned over, elementsdescribed as being on the “lower” side of other elements would then beoriented on “upper” sides of the other elements. The exemplary term“lower,” can therefore, encompasses both an orientation of “lower” and“upper,” depending on the particular orientation of the figure.Similarly, if the device in one of the figures is turned over, elementsdescribed as “below” or “beneath” other elements would then be oriented“above” the other elements. The exemplary terms “below” or “beneath”can, therefore, encompass both an orientation of above and below.

“About” or “approximately” as used herein is inclusive of the statedvalue and means within an acceptable range of deviation for theparticular value as determined by one of ordinary skill in the art,considering the measurement in question and the error associated withmeasurement of the particular quantity (i.e., the limitations of themeasurement system). For example, “about” can mean within one or morestandard deviations, or within ±30%, 20%, 10% or 5% of the stated value.

Unless otherwise defined, all terms (including technical and scientificterms) used herein have the same meaning as commonly understood by oneof ordinary skill in the art to which this disclosure belongs. It willbe further understood that terms, such as those defined in commonly useddictionaries, should be interpreted as having a meaning that isconsistent with their meaning in the context of the relevant art and thepresent disclosure, and will not be interpreted in an idealized oroverly formal sense unless expressly so defined herein.

Exemplary embodiments are described herein with reference to crosssection illustrations that are schematic illustrations of idealizedembodiments. As such, variations from the shapes of the illustrations asa result, for example, of manufacturing techniques and/or tolerances,are to be expected. Thus, embodiments described herein should not beconstrued as limited to the particular shapes of regions as illustratedherein but are to include deviations in shapes that result, for example,from manufacturing. For example, a region illustrated or described asflat may, typically, have rough and/or nonlinear features. Moreover,sharp angles that are illustrated may be rounded. Thus, the regionsillustrated in the figures are schematic in nature and their shapes arenot intended to illustrate the precise shape of a region and are notintended to limit the scope of the present claims.

According to an embodiment, an organic light-emitting device includes afirst electrode, a second electrode facing the first electrode, and anemission layer located between the first electrode and the secondelectrode, wherein the emission layer includes a host and a thermallyactivated delayed fluorescence emitter.

In one embodiment, the host may include a compound represented byFormula 1, a compound represented by Formula 2, or a combinationthereof:

In Formulae 1 and 2, Z₁ to Z₆ may each independently be:

hydrogen, deuterium, —F, —Cl, —Br, —I, or a cyano group; or

a C₁-C₂₀ alkyl group, a phenyl group, a biphenyl group, a terphenylgroup, a dibenzofuranyl group, or a dibenzothiophenyl group, eachunsubstituted or substituted with deuterium, —F, —Cl, —Br, —I, a cyanogroup, a C₁-C₂₀ alkyl group, a phenyl group, a biphenyl group, or anycombination thereof.

In an exemplary embodiment, Z₁ to Z₆ may each independently be:

hydrogen, deuterium, or a cyano group; or

a C₁-C₁₀ alkyl group, a phenyl group, a biphenyl group, a terphenylgroup, a dibenzofuranyl group, or a dibenzothiophenyl group, eachunsubstituted or substituted with deuterium, a cyano group, a C₁-C₁₀alkyl group, a phenyl group, a biphenyl group, or any combinationthereof.

In one embodiment, Z₁ to Z₆ may each independently be:

hydrogen, deuterium, or a cyano group; or

a C₃-C₁₀ alkyl group, a phenyl group, a biphenyl group, a terphenylgroup, a dibenzofuranyl group, or a dibenzothiophenyl group, eachunsubstituted or substituted with deuterium, a cyano group, a C₃-C₁₀alkyl group, a phenyl group, a biphenyl group, or any combinationthereof.

In one or more embodiments, Z₁ to Z₆ may each independently be:

hydrogen, deuterium, or a cyano group; or

an n-propyl group, an isopropyl group, an n-butyl group, an isobutylgroup, a sec-butyl group, a tert-butyl group, an n-pentyl group, anisopentyl group, a sec-pentyl group, a tert-pentyl group, a phenylgroup, a biphenyl group, or a terphenyl group, each unsubstituted orsubstituted with deuterium, a cyano group, an n-propyl group, anisopropyl group, an n-butyl group, an isobutyl group, a sec-butyl group,a tert-butyl group, an n-pentyl group, an isopentyl group, a sec-pentylgroup, a tert-pentyl group, a phenyl group, a biphenyl group, or anycombination thereof, but embodiments of the present disclosure are notlimited thereto.

In Formula 1, b1 to b6 each indicate the number of Z₁ to the number ofZ₆, respectively, and may each independently be 1, 2, 3, or 4. When b1to b6 are each independently two or more, two or more of each of Z₁ toZ₆ may be identical to or different from each other.

In an exemplary embodiment, b1 to b6 may each independently be 0, 1, or2, but embodiments of the present disclosure are not limited thereto.

In Formulae 1 and 2, at least one of, i) Z₁ in the number of b1, ii) Z₂in the number of b2, iii) Z₃ in the number of b3, iv) Z₄ in the numberof b4, v) Z₅ in the number of b5, and vi) R₆ in the number of b6 may bea cyano group. That is, Formulae 1 and 2 may each independently includeat least one cyano group.

In one embodiment, the number of cyano group(s) included in the compoundrepresented by Formula 1 and the number of cyano group(s) included inthe compound represented by Formula 2 may each independently be 1, 2, 3,or 4, but embodiments of the present disclosure are not limited thereto.

In one or more embodiments, in Formulae 1 and 2,

at least one (for example, 1, 2, 3, or 4) of, i) Z₁ in the number of b1and ii) Z₂ in the number of b2 may be a cyano group;

at least one (for example, 1, 2, 3, or 4) of, i) Z₃ in the number of b3and ii) Z₄ in the number of b4 may be a cyano group;

at least one (for example, 1, 2, 3, or 4) of, i) Z₅ in the number of b5and ii) Z₆ in the number of b6 may be a cyano group;

at least one (for example, 1 or 2) of, i) Z₁ in the number of b1 and ii)Z₂ in the number of b2 may be a cyano group, and at least one (forexample, 1 or 2) of, i) Z₃ in the number of b3 and ii) Z₄ in the numberof b4 may be a cyano group;

at least one (for example, 1 or 2) of, i) Z₁ in the number of b1 and ii)Z₂ in the number of b2 may be a cyano group, and at least one (forexample, 1 or 2) of, i) Z₅ in the number of b5 and ii) Z₆ in the numberof b6, may be a cyano group;

at least one (for example, 1 or 2) of, i) Z₃ in the number of b3 and ii)Z₄ in the number of b4 may be a cyano group, and at least one (forexample, 1 or 2) of, i) Z₅ in the number of b5 and ii) Z₆ in the numberof b6 may be a cyano group; or

at least one (for example, 1 or 2) of i) Z₁ in the number of b1 and ii)Z₂ in the number of b2 may be a cyano group, at least one (for example,1 or 2) of, i) Z₃ in the number of b3 and ii) Z₄ in the number of b4 maybe a cyano group, and at least one (for example, 1 or 2) of, i) Z₅ inthe number of b5 and ii) Z₆ in the number of b6 may be a cyano group.

In one embodiment, a group represented by

in Formula 1 may be a group represented by one of Formulae PO1 to PO25,and/or

a group represented by

in Formula 2 may be a group represented by one of Formulae PM1 to PM25:

In Formulae PO1 to PO25 and PM1 to PM25, Z₁₀ to Z₁₉ are each defined thesame as Z₃ and Z₄, and * and *′ each indicate a binding site to aneighboring nitrogen atom.

In one embodiment, in Formulae PO1 to PO25 and PM1 to PM25, Z₁₀ to Z₁₉may not be a cyano group.

In one or more embodiments, in Formulae PO1 to PO25 and PM1 to PM25, Z₁₀to Z₁₉ may each independently be:

hydrogen, deuterium, —F, —Cl, —Br, —I, or a cyano group; or

a C₁-C₂₀ alkyl group, a phenyl group, a biphenyl group, a terphenylgroup, a dibenzofuranyl group, or a dibenzothiophenyl group, eachunsubstituted or substituted with deuterium, —F, —Cl, —Br, —I, a cyanogroup, a C₁-C₂₀ alkyl group, a phenyl group, a biphenyl group, or anycombination thereof.

In one or more embodiments, in Formulae PO1 to PO25 and PM1 to PM25, Z₁₀to Z₁₉ may each independently be:

hydrogen, deuterium, or a cyano group; or

an-propyl group, an isopropyl group, an n-butyl group, an isobutylgroup, a sec-butyl group, a tert-butyl group, an n-pentyl group, anisopentyl group, a sec-pentyl group, a tert-pentyl group, a phenylgroup, a biphenyl group, or a terphenyl group, each unsubstituted orsubstituted with deuterium, a cyano group, an n-propyl group, anisopropyl group, an n-butyl group, an isobutyl group, a sec-butyl group,a tert-butyl group, an n-pentyl group, an isopentyl group, a sec-pentylgroup, a tert-pentyl group, a phenyl group, a biphenyl group, or anycombination thereof.

In one or more embodiments, a group represented by

in Formulae 1 and 2 may be a group represented by one of Formulae A1-1to A1-3, and/or

a group represented by

in Formulae 1 and 2 may be a group represented by one of Formulae A2-1to A2-3:

In Formulae A1-1 to A1-3 and A2-1 to A2-3, Z₂₁ to Z₂₈ and Z₃₁ to Z₃₈ mayeach independently be:

hydrogen, deuterium, —F, —Cl, —Br, —I, or a cyano group; or

a C₁-C₂₀ alkyl group, a phenyl group, a biphenyl group, a terphenylgroup, a dibenzofuranyl group, or a dibenzothiophenyl group, eachunsubstituted or substituted with deuterium, —F, —Cl, —Br, —I, a cyanogroup, a C₁-C₂₀ alkyl group, a phenyl group, a biphenyl group, or anycombination thereof, and

* and *′ each indicate a binding site to a neighboring carbon atom.

In an exemplary embodiment, in Formulae A1-1 to A1-3 and A2-1 to A2-3,Z₂₁ to Z₂₈ and Z₃₁ to Z₃₈ may not a cyano group.

In one or more embodiments, the host may include at least one ofCompounds EH1 to EH15:

Two carbazole rings included in each of Formulae 1 and 2 may be linkedto each other via a biphenylene linking group. Here, one of the twocarbazole rings is linked to a carbon atom at a “para” position withrespect to carbon atoms to which two benzene rings of the biphenylenelinking group are linked, whereas the other one of the two carbazolerings is linked to a carbon atom at an “ortho” position (see Formula 1)or a “meta” position (See Formula 2), with respect to carbon atoms towhich two benzene rings of the biphenylene linking group are linked. Inthis regard, Formulae 1 and 2 may each have an asymmetric structure inwhich two carbazole rings are linked to each other via the biphenylenelinking group, and accordingly, Formulae 1 and 2 may each have a highdipole moment. Thus, an electronic device, for example, an organiclight-emitting device, including the compound represented by Formula 1,the compound represented by Formula 2, or a combination thereof, mayhave excellent luminescence efficiency.

In an exemplary embodiment, the dipole moment of each of the compoundrepresented by Formula 1 and the compound represented by Formula 2 maybe about 6.4 debye or more, and for example, may be in a range of about7.0 debye to about 15.0 debye (for example, in a range of about 9.0debye to about 13.0 debye), but embodiments of the present disclosureare not limited thereto.

To evaluate the dipole moment, the electrostatic potential fitting (ESP)charge of each atom of the relevant compounds and the distance betweenatoms are obtained by using a Density Functional Theory (DFT) method ofa Jaguar program (that is structurally optimized at a level of B3LYP,6-31G(d,p), and then, the dipole moment of the relevant compounds may becalculated therefrom.

The compound represented by Formula 1 and the compound represented by 2may each have a high dipole moment as described above, and at the sametime, may not include a group represented by *=o (where * indicates abinding site to a neighboring atom) (for example, a phosphineoxide-containing compound may include a group represented by *=o). Inthis regard, the compound represented by Formula 1 and the compoundrepresented by 2 may stabilize the charge transfer excited state of thethermally activated delayed fluorescence emitter, thereby significantlyincreasing a delayed fluorescence component in the emission layer.Therefore, use of the emission layer including the host and thethermally activated delayed fluorescence emitter, wherein the hostincludes the compound represented by Formula 1, the compound representedby 2, or a combination thereof may achieve a high luminescenceefficiency. Also, when storing and/or driving an organic light-emittingdevice, a material for the emission layer may be substantially preventedfrom being decomposed by the group represented by *=o, thereby realizingan organic light-emitting device having a high luminescence efficiencyand a long lifespan “at the same time”.

In addition, the compound represented by Formula 1 and the compoundrepresented by 2 may each include at least one cyano group, andaccordingly, may each have excellent electron transport characteristicsand relatively high triplet energy levels.

A difference between a triplet energy level of the host and a tripletenergy level of the thermally activated delayed fluorescence emitter maybe greater than or equal to about 0.2 electron volts (eV) to less thanor equal to about 0.5 eV. When the difference of the triplet energylevels between the host and the thermally activated delayed fluorescenceemitter is within the range above, the energy of triplet excitonsgenerated in the thermally activated delayed fluorescence emitter may beprevented from leaking to the host in the emission layer, therebyrealizing efficient light emission. In addition, due to a suppressedactivation exciton energy level of the host, the long lifespan of theorganic light-emitting device may be realized.

The triplet energy level may be evaluated by using a DFT method of aGaussian program that is structurally optimized at a level ofB3LYP/6-31G(d,p).

The thermally activated delayed fluorescence emitter may be a compoundcapable of emitting delayed fluorescence according to an emissionmechanism of the thermally activated delayed fluorescence emitter.

In one embodiment, a difference between a triplet energy level of thethermally activated delayed fluorescence emitter and a singlet energylevel of the thermally activated delayed fluorescence emitter may begreater than or equal to about 0 eV to less than or equal to about 0.5eV. When the difference between the triplet energy level of thethermally activated delayed fluorescence emitter and the singlet energylevel of the thermally activated delayed fluorescence emitter is withinthe range above, the up-conversion from the triplet state to the singletstate may be efficiently performed, so that the thermally activateddelayed fluorescence emitter may be able to emit delayed fluorescencewith a high efficiency.

The triplet energy level and the singlet energy level may each beevaluated by using a DFT method of a Gaussian program that isstructurally optimized at a level of B3LYP/6-31G (d,p).

In one embodiment, the thermally activated delayed fluorescence emittermay include a compound represented by Formula 11:

In Formula 11, X₁ may be a single bond, N-[(L₄)_(c4)-R₄], C(R₅)(R₆), O,or S.

In an exemplary embodiment, X₁ may be a single bond, but embodiments ofthe present disclosure are not limited thereto.

In Formula 11, A₁ and A₂ may each independently be a benzene group, anaphthalene group, an indene group, an indole group, a benzofuran group,a benzothiophene group, a benzosilole group, a fluorene group, acarbazole group, a dibenzofuran group, a dibenzothiophene group, adibenzosilole group, an indolofluorene group, an indolocarbazole group,an indolodibenzofuran group, an indolodibenzothiophene group, anindenofluorene group, an indenocarbazole group, an indenodibenzofurangroup, an indenodibenzothiophene group, a benzofuranofluorene group, abenzofuranocarbazole group, a benzofuranodibenzofuran group, abenzofuranodibenzothiophene group, a benzothienofluorene group, abenzothienocarbazole group, a benzothienodibenzofuran group, or abenzothienodibenzothiophene group.

In an exemplary embodiment, A₁ and A₂ may each independently be abenzene group, a fluorene group, a carbazole group, a dibenzofurangroup, a dibenzothiophene group, or a dibenzosilole group, and A₁, A₂,or a combination thereof may each independently be a benzene group.However, embodiments of the present disclosure are not limited thereto.

L₃ and L₄ may each independently be a substituted or unsubstitutedcycloalkylene group, a substituted or unsubstituted C₂-C₁₀heterocycloalkylene group, a substituted or unsubstituted C₃-C₁₀cycloalkenylene group, a substituted or unsubstituted C₂-C₁₀heterocycloalkenylene group, a substituted or unsubstituted C₆-C₆₀arylene group, a substituted or unsubstituted C₁-C₆₀ heteroarylenegroup, a substituted or unsubstituted divalent non-aromatic condensedpolycyclic group, or a substituted or unsubstituted divalentnon-aromatic condensed heteropolycyclic group.

In an exemplary embodiment, L₃ and L₄ may each independently be:

a phenylene group, a naphthylene group, a fluorenylene group, apyridinylene group, a pyrimidinylene group, a pyrazinylene group, apyridazinylene group, a triazinylene group, a quinolinylene group, anisoquinolinylene group, a carbazolylene group, a dibenzofuranylenegroup, a dibenzothiophenylene group, or an indolocarbazolylene group; or

a phenylene group, a naphthylene group, a fluorenylene group, apyridinylene group, a pyrimidinylene group, a pyrazinylene group, apyridazinylene group, a triazinylene group, a quinolinylene group, anisoquinolinylene group, a carbazolylene group, a dibenzofuranylenegroup, a dibenzothiophenylene group, or an indolocarbazolylene group,each substituted with deuterium, a C₁-C₁₀ alkyl group, a alkoxy group, aphenyl group, a biphenyl group, a terphenyl group, a naphthyl group, afluorenyl group, a pyridinyl group, a pyrimidinyl group, a pyrazinylgroup, a pyridazinyl group, a triazinyl group, a quinolinyl group, anisoquinolinyl group, a carbazolyl group, a dibenzofuranyl group, adibenzothiophenyl group, an indolocarbazolyl group, —Si(Q₃₁)(Q₃₂)(Q₃₃),—N(Q₃₄)(Q₃₅), or any combination thereof, and

Q₃₁ to Q₃₅ may each independently be a C₁-C₁₀ alkyl group, a C₁-C₁₀alkoxy group, a phenyl group, a biphenyl group, a terphenyl group, or anaphthyl group. However, embodiments of the present disclosure are notlimited thereto.

In one embodiment, at least one of L₃(s) in the number of c3 in Formula11 may be a group represented Formulae L-1 or L-2, but embodiments ofthe present disclosure are not limited thereto:

In Formulae L-1 and L-2, R₄₁ to R₅₂ may each independently be hydrogen,deuterium, a C₁-C₁₀ alkyl group, a C₁-C₁₀ alkoxy group, a phenyl group,a biphenyl group, a terphenyl group, a naphthyl group, a fluorenylgroup, a pyridinyl group, a pyrimidinyl group, a pyrazinyl group, apyridazinyl group, a triazinyl group, a quinolinyl group, anisoquinolinyl group, a carbazolyl group, a dibenzofuranyl group, adibenzothiophenyl group, an indolocarbazolyl group, —Si(Q₃₁)(Q₃₂)(Q₃₃),or —N(Q₃₄)(Q₃₅), Q₃₁ to Q₃₅ are each independently the same as describedherein, * indicates a binding site to a neighboring atom, and *′indicates a binding site to L₃ or R₃.

In one embodiment, c3 and c4 each indicate the number of L₃ and thenumber of L₄, respectively, and may each independently be an integerfrom 0 to 4. When c3 is two or more, two or more L₃ may be identical toor different from each other, and when c4 is two or more, two or more L₄may be identical to or different from each other. In an exemplaryembodiment, c3 and c4 may each independently be 0, 1, or 2, butembodiments of the present disclosure are not limited thereto.

In Formula 11, R₁ to R₅ may each independently be hydrogen, deuterium,—F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, anamino group, an amidino group, a hydrazine group, a hydrazone group, acarboxylic acid group or a salt thereof, a sulfonic acid group or a saltthereof, a phosphoric acid group or a salt thereof, a substituted orunsubstituted C₁-C₆₀ alkyl group, a substituted or unsubstituted C₂-C₆₀alkenyl group, a substituted or unsubstituted C₂-C₆₀ alkynyl group, asubstituted or unsubstituted C₁-C₆₀ alkoxy group, a substituted orunsubstituted C₃-C₁₀ cycloalkyl group, a substituted or unsubstitutedC₂-C₁₀ heterocycloalkyl group, a substituted or unsubstituted C₃-C₁₀cycloalkenyl group, a substituted or unsubstituted C₂-C₁₀heterocycloalkenyl group, a substituted or unsubstituted C₆-C₆₀ arylgroup, a substituted or unsubstituted C₆-C₆₀ aryloxy group, asubstituted or unsubstituted C₆-C₆₀ arylthio group, a substituted orunsubstituted C₁-C₆₀ heteroaryl group, a substituted or unsubstitutedmonovalent non-aromatic condensed polycyclic group, a substituted orunsubstituted monovalent non-aromatic condensed heteropolycyclic group,—Si(Q₁)(Q₂)(Q₃), —N(Q₄)(Q₅), or —B(Q₆)(Q₇), and Q₁ to Q₇ are eachindependently the same as described herein.

In one embodiment, R₃ in Formula 11 may include at least one πelectron-depleted nitrogen-containing cyclic group.

In the present specification, the term “π electron-depletednitrogen-containing cyclic group” as used herein indicates a groupincluding a cyclic group having at least one of *—N═*′ moiety. In anexemplary embodiment, the π electron-depleted nitrogen-containing cyclicgroup may be an imidazole group, a pyrazole group, a thiazole group, anisothiazole group, an oxazole group, an isoxazole group, a pyridinegroup, a pyrazine group, a pyridazine group, a pyrimidine group, anindazole group, a purine group, a quinoline group, an isoquinolinegroup, a benzoquinoline group, a benzoisoquinoline, a phthalazine group,a naphthyridine group, a quinoxaline group, a benzoquinoxaline group, aquinazoline group, a cinnoline group, a phenanthridine group, anacridine group, a phenanthroline group, a phenazine group, abenzimidazole group, an isobenzothiazole group, a benzoxazole group, anisobenzoxazole group, a triazole group, a tetrazole group, an oxadiazolegroup, a triazine group, a thiadiazole group, an imidazopyridine group,an imidazopyrimidine group, an azaindene group, an azaindole group, anazabenzofuran group, an azabenzothiophene group, an azabenzosilolegroup, an azafluorene group, an azacarbazole group, an azadibenzofurangroup, an azadibenzothiophene group, or an azadibenzosilole group.

In one or more embodiments, R₃ in Formula 11 may be:

a phenyl group, an indenyl group, a naphthyl group, a fluorenyl group, aspiro-bifluorenyl group, a benzofluorenyl group, a dibenzofluorenylgroup, a phenanthrenyl group, an anthracenyl group, a fluoranthenylgroup, a triphenylenyl group, a pyrenyl group, a chrysenyl group, apyrrolyl group, an isoindolyl group, an indolyl group, a furanyl group,a thiophenyl group, a silolyl group, a benzofuranyl group, abenzothiophenyl group, a benzosilolyl group, a carbazolyl group, adibenzofuranyl group, a dibenzothiophenyl group, a dibenzosilolyl group,an indeno carbazolyl group, an indolocarbazolyl group, abenzofuracarbazolyl group, a benzothienocarbazolyl group, abenzosilolocarbazolyl group, an imidazolyl group, a pyrazolyl group, athiazolyl group, an isothiazolyl group, an oxazolyl group, an isoxazolylgroup, a pyridinyl group, a pyrazinyl group, a pyridazinyl group, apyrimidinyl group, an indazolyl group, a purinyl group, a quinolinylgroup, an isoquinolinyl group, a benzoquinolinyl group, abenzoisoquinolinyl group, a phthalazinyl group, a naphthyridinyl group,a quinoxalinyl group, a benzoquinoxalinyl group, a quinazolinyl group, acinnolinyl group, a phenanthridinyl group, an acridinyl group, aphenanthrolinyl group, a phenazinyl group, a benzimidazolyl group, anisobenzothiazolyl group, a benzoxazolyl group, an isobenzoxazolyl group,a triazolyl group, a tetrazolyl group, an oxadiazolyl group, a triazinylgroup, a thiadiazolyl group, an imidazopyridinyl group, animidazopyrimidinyl group, an azaindenyl group, an azaindolyl group, anazabenzofuranyl group, an azabenzothiophenyl group, an azabenzosilolylgroup, an azafluorenyl group, an azacarbazolyl group, anazadibenzofuranyl group, an azadibenzothiophenyl group, or anazadibenzosilolyl group, each unsubstituted or substituted withdeuterium, a C₁-C₁₀ alkyl group, a C₁-C₁₀ alkoxy group, a phenyl group,a (C₁-C₁₀ alkyl)phenyl group, a di(C₁-C₁₀ alkyl)phenyl group, a biphenylgroup, a terphenyl group, a di(phenyl)phenyl group, a di(biphenyl)phenylgroup, a (pyridinyl)phenyl group, a di(pyridinyl)phenyl group, a(pyrimidinyl)phenyl group, a di(pyrimidinyl)phenyl group, a(triazinyl)phenyl group, a di(triazinyl)phenyl group, a pyridinyl group,a (C₁-C₁₀ alkyl)pyridinyl group, a di(C₁-C₁₀ alkyl)pyridinyl group, a(phenyl)pyridinyl group, a di(phenyl)pyridinyl group, a(biphenyl)pyridinyl group, a di(biphenyl)pyridinyl group, a(terphenyl)pyridinyl group, a bi(terphenyl)pyridinyl group, a(pyridinyl)pyridinyl group, a di(pyridinyl)pyridinyl group, a(pyrimidinyl)pyridinyl group, a di(pyrimidinyl)pyridinyl group, a(triazinyl)pyridinyl group, a di(triazinyl)pyridinyl group, apyrimidinyl group, a (C₁-C₁₀ alkyl)pyrimidinyl group, a di(C₁-C₁₀alkyl)pyrimidinyl group, a (phenyl)pyrimidinyl group, adi(phenyl)pyrimidinyl group, a (biphenyl)pyrimidinyl group, adi(biphenyl)pyrimidinyl group, a (terphenyl)pyrimidinyl group, abi(terphenyl)pyrimidinyl group, a (pyridinyl)pyrimidinyl group, adi(pyridinyl)pyrimidinyl group, a (pyrimidinyl)pyrimidinyl group, adi(pyrimidinyl)pyrimidinyl group, a (triazinyl)pyrimidinyl group, adi(triazinyl)pyrimidinyl group, a triazinyl group, a (C₁-C₁₀alkyl)triazinyl group, a di(C₁-C₁₀ alkyl)triazinyl group, a(phenyl)triazinyl group, a di(phenyl)triazinyl group, a(biphenyl)triazinyl group, a di(biphenyl)triazinyl group, a(terphenyl)triazinyl group, a bi(terphenyl)triazinyl group, a(pyridinyl)triazinyl group, a di(pyridinyl)triazinyl group, a(pyrimidinyl)triazinyl group, a di(pyrimidinyl)triazinyl group, a(triazinyl)triazinyl group, a di(triazinyl)triazinyl group, a fluorenylgroup, a di(C₁-C₁₀ alkyl)fluorenyl group, a di(phenyl)fluorenyl group, adi(biphenyl)fluorenyl group, a carbazolyl group, a (C₁-C₁₀alkyl)carbazolyl group, a (phenyl)carbazolyl group, a(biphenyl)carbazolyl group, a dibenzofuranyl group, a (C₁-C₁₀alkyl)dibenzofuranyl group, a (phenyl)dibenzofuranyl group, a(biphenyl)dibenzofuranyl group, a dibenzothiophenyl group, a (C₁-C₁₀alkyl)dibenzothiophenyl group, a (phenyl)dibenzothiophenyl group, a(biphenyl)dibenzothiophenyl group, or any combination thereof, butembodiments of the present disclosure are not limited thereto.

In one or more embodiments, in R₃ in Formula 11 may be:

a group represented by Formula 13(1) or a group represented by Formula13(2);

a phenyl group, a biphenyl group, a terphenyl group, a naphthyl group, afluorenyl group, a quinolinyl group, an isoquinolinyl group, acarbazolyl group, a dibenzofuranyl group, a dibenzothiophenyl group, oran indolocarbazolyl group; or

a phenyl group, a biphenyl group, a terphenyl group, a naphthyl group, afluorenyl group, a quinolinyl group, an isoquinolinyl group, acarbazolyl group, a dibenzofuranyl group, a dibenzothiophenyl group, oran indolocarbazolyl group, each substituted with deuterium, a C₁-C₁₀alkyl group, a C₁-C₁₀ alkoxy group, a phenyl group, a biphenyl group, aterphenyl group, a naphthyl group, a fluorenyl group, a pyridinyl group,a pyrimidinyl group, a pyrazinyl group, a pyridazinyl group, a triazinylgroup, a quinolinyl group, an isoquinolinyl group, a carbazolyl group, adibenzofuranyl group, a dibenzothiophenyl group, an indolocarbazolylgroup, —Si(Q₃₁)(Q₃₂)(Q₃₃), or any combination thereof, and

Q₃₁ to Q₃₃ may each independently be a C₁-C₁₀ alkyl group, a C₁-C₁₀alkoxy group, a phenyl group, a biphenyl group, a terphenyl group, or anaphthyl group:

In Formula 13(1), X₁₁ to X₁₅ may each independently be C or N, and atleast one of X₁₁ to X₁₅ may be N.

In an exemplary embodiment, two or three of X₁₁ to X₁₅ may eachindependently be N.

In Formula 13(2), A₁₁ and A₁₂ may each independently be a benzene group,a naphthalene group, a pyridine group, a pyrazine group, a pyrimidinegroup, a pyridazine group, a quinoline group, an isoquinoline group, aquinoxaline group, or a quinazoline group, and A₁₁, A₁₂, or acombination thereof may each independently be a pyridine group, apyrazine group, a pyrimidine group, a pyridazine group, a quinolinegroup, an isoquinoline group, a quinoxaline group, a quinazoline group,or a combination thereof.

In an exemplary embodiment, A₁₁ may be a pyridine group, a pyrimidinegroup, a quinoline group, an isoquinoline group, a quinoxaline group, ora quinazoline group, and A₁₂ may be a benzene group or a naphthalenegroup, but embodiments of the present disclosure are not limitedthereto.

In Formula 13(2), X₁₆ may be N-[(L₁₂)_(a12)-R₁₂], C(R₁₄)(R₁₅), O, or S,and X₁₇ may be a single bond, N-[(L₁₃)_(a13)-R₁₃], C(R₁₆)(R₁₇), O or S.

In an exemplary embodiment, X₁₆ may be O or S, and X₁₇ may be a singlebond, but embodiments of the present disclosure are not limited thereto.

In Formulae 13(1) and 13(2), L₁₁ to L₁₃ are each independently definedthe same as L₃, a11 to a13 are each independently defined the same asc3, and R₁₁ to R₁₇ are each independently defined the same as R₁.

In Formula 13(2), d16 may be an integer from 0 to 6. In Formula 13(1),d14 may be an integer from 0 to 4.

In Formulae 13(1) and 13(2), * indicates a binding site to a neighboringatom.

In one embodiment, R₃ in Formula 11 may be a group represented by one ofFormulae 13-1 to 13-20, but embodiments of the present disclosure arenot limited thereto:

In Formulae 13-1 to 13-20,

X₁₆ may be N-[(L₁₂)_(a12)-R₁₂], C(R₁₄)(R₁₅), O, or S,

L₁₁ and L₁₂ are each independently defined the same as L₃,

a11 and a12 are each independently defined the same as c3,

R₁₁, R₁₂, R₁₄, and R₁₅ are each independently defined the same as R₁,

d16 may be an integer from 0 to 6,

d15 may be an integer from 0 to 5,

d14 may be an integer from 0 to 4,

d13 may be an integer from 0 to 3,

d12 may be an integer from 0 to 2, and

* indicates a binding site to a neighboring atom.

In one embodiment, in Formula 11, R₁, R₂, R₅, and R₆ may eachindependently be hydrogen, deuterium, a C₁-C₁₀ alkyl group, a C₁-C₁₀alkoxy group, a phenyl group, a biphenyl group, a terphenyl group, anaphthyl group, a fluorenyl group, a pyridinyl group, a pyrimidinylgroup, a pyrazinyl group, a pyridazinyl group, a triazinyl group, acarbazolyl group, a dibenzofuranyl group, a dibenzothiophenyl group, anindolocarbazolyl group, —Si(Q₁)(Q₂)(Q₃), or —N(Q₄)(Q₅),

Q₁ to Q₅ may each independently be a C₁-C₁₀ alkyl group, a C₁-C₁₀ alkoxygroup, a phenyl group, a biphenyl group, a terphenyl group, or anaphthyl group.

In Formula 11, a1 and a2 each indicate the number of R₁ and the numberof R₂, respectively, and may each independently be an integer from 0 to10. When a1 is two or more, two or more R₁ may be identical to ordifferent from each other, and when a2 is two or more, two or more R₂may be identical to or different from each other.

In one embodiment, the thermally activated delayed fluorescence emittermay include a compound represented by one of Formulae 11-1 to 11-7, butembodiments of the present disclosure are not limited thereto:

In Formulae 11-1 to 11-7,

X₁, L₃, c3, and R₁ to R₃ are each independently the same describedherein,

X₂ may be N-[(L₅)_(c5)-R₇], C(R₈)(R₉), O, or S,

L₅ and c5 are each independently defined the same as L₃ and c3,respectively,

R₇ is defined the same as R₃,

R₈ and R₉ are each independently defined the same as R₅ and R₆,respectively,

a16 may be an integer from 0 to 6, and

a14 and a24 may each independently be an integer from 0 to 4.

In one embodiment, in Formulae 11-1 to 11-17, 1) R₃ in the case where X₂is C(R₈)(R₉), O, or S, and 2) R₃, R₇, or a combination thereof, in thecase where X₂ is N-[(L₅)_(c5)-R₇] may each independently include atleast one π electron-depleted nitrogen-containing cyclic group describedabove.

In one or more embodiments, in Formulae 11-1 to 11-17, 1) R₃ in the casewhere X₂ is C(R₈)(R₉), O, or S, and 2) R₃ and R₇ in the case where X₂ isN-[(L₅)_(c5)-R₇] may each independently be:

a group represented by Formula 13(1) or a group represented by Formula13(2) (for example, one of the groups represented by Formulae 13-1 to13-20);

a phenyl group, a biphenyl group, a terphenyl group, a naphthyl group, afluorenyl group, a quinolinyl group, an isoquinolinyl group, acarbazolyl group, a dibenzofuranyl group, a dibenzothiophenyl group, oran indolocarbazolyl group; and

a phenyl group, a biphenyl group, a terphenyl group, a naphthyl group, afluorenyl group, a quinolinyl group, an isoquinolinyl group, acarbazolyl group, a dibenzofuranyl group, a dibenzothiophenyl group, oran indolocarbazolyl group, each substituted with deuterium, a C₁-C₁₀alkyl group, a C₁-C₁₀ alkoxy group, a phenyl group, a biphenyl group, aterphenyl group, a naphthyl group, a fluorenyl group, a pyridinyl group,a pyrimidinyl group, a pyrazinyl group, a pyridazinyl group, a triazinylgroup, a quinolinyl group, an isoquinolinyl group, a carbazolyl group, adibenzofuranyl group, a dibenzothiophenyl group, an indolocarbazolylgroup, —Si(Q₃₁)(Q₃₂)(Q₃₃), or any combination thereof, and

1) R₃ in the case where X₂ is C(R₈)(R₉), O, or S, R₃ and 2) R₃, R₇, or acombination thereof in the case where X₂ is N-[(L₅)_(c5)-R₇] may eachindependently be a group represented by Formula 13(1) or a grouprepresented by Formula 13(2) (for example, one of the groups representedby Formulae 13-1 to 13-20).

In one embodiment, the thermally activated delayed fluorescence emittermay include a compound represented by Formula 14A:

In Formula 14A, R₂₁ to R₂₅ may each independently be hydrogen,deuterium, a cyano group, a C₁-C₁₀ alkyl group, a phenyl group, abiphenyl group, or a terphenyl group.

In one embodiment, the thermally activated delayed fluorescence emittermay not include a cyano group.

The thermally activated delayed fluorescence emitter may include atleast one of Compounds D1-1 to D1-83, D2-1 to D2-81, D3-1 to D3-81, D201to D211, 1 to 1030, and TD1 to TD4, but embodiments of the presentdisclosure are not limited thereto:

The emission layer including the host and the thermally activateddelayed fluorescence emitter may not include a transitionmetal-containing organometallic compound. That is, the emission layer isclearly distinguished from a phosphorescence layer which includes atransition metal-containing organometallic compound and emitsphosphorescence from the transition metal-containing organometalliccompound.

A portion of delayed fluorescence components emitted by the thermallyactivated delayed fluorescence emitter in total luminescence componentsemitted by the emission layer including the host and the thermallyactivated delayed fluorescence emitter may be about 90% or more, about92% or more, about 94% or more, about 96% or more, or about 98% or more.

The emission layer may emit red light, green light, and/or blue light invarious ways according to a maximum emission wavelength of the thermallyactivated delayed fluorescence emitter.

In one embodiment, the light emitted by the thermally activated delayedfluorescence emitter in the emission layer may be blue light, butembodiments of the present disclosure are not limited thereto.

An amount of the thermally activated delayed fluorescence emitter in theemission layer may be in a range of about 0.01 parts by weight to about30 parts by weight based on 100 parts by weight of the host, butembodiments of the present disclosure are not limited thereto. When theamount of fluorescence emitted by the thermally activated delayedfluorescence emitter is within the range above, a high-quality organiclight-emitting device without density extinction phenomenon may berealized.

In one embodiment, the emission layer may include the host and thethermally activated delayed fluorescence emitter, but may not include aphosphorescent compound (for example, a transition metal-containingorganometallic compound). Thus, the organic light-emitting deviceincluding the emission layer may emit not phosphorescence, but delayedfluorescence, thereby having both a high efficiency and a long lifespan.

According to one or more exemplary embodiments, the host in the emissionlayer may include a first material and a second material. The firstmaterial and the second material may be different from each other, andthe second material may include the compound represented by Formula 1,the compound represented by Formula 2, or a combination thereof.Formulae 1 and 2 are each independently the same as described herein.

The first material may be a hole transport material. In an exemplaryembodiment, the first material may not include an electron transportmoiety.

In an exemplary embodiment, the first material may not include a cyanogroup, a π electron-depleted nitrogen-containing cyclic group, and agroup represented by the following formulae:

In the formulae above, *, *′, and *″ each indicate a binding site to aneighboring atom.

In one embodiment, the first material may include at least one πelectron-depleted nitrogen-free cyclic group, and may not include anelectron transport moiety.

In one or more embodiments, the first material may include at least onecarbazole group.

In one or more embodiments, the first material may include two or morecarbazole groups, but embodiments of the present disclosure are notlimited thereto.

In one or more embodiments, the first material may include a benzenegroup not including a cyano group and a carbazole group not including acyano group.

In one or more embodiments, the first material may have an absolutevalue of a lowest unoccupied molecular orbital (LUMO) energy level ofgreater than or equal to about 0.90 eV to less than or equal to about1.20 eV, and an absolute value of a highest occupied molecular orbital(HOMO) energy level of greater than or equal to about 5.20 eV to lessthan or equal to about 5.60 eV.

When the first material has the HOMO energy level and the LUMO energylevel within the ranges above, the movement of charges and/or excitonsin the emission layer and the energy flow may be smoothly performed,thereby realizing the organic light-emitting device having a highluminescence efficiency and a long lifespan.

In one or more embodiments, the first material may include a compoundrepresented by Formula H-1(1), a compound represented by Formula H-1(2),a compound represented by Formula H-1(3), or a combination thereof:

In Formulae H-1(1) to H-1(3), ring A₄₁ to ring A₄₄ may eachindependently be a benzene group, a naphthalene group, an indene group,an indole group, a benzofuran group, a benzothiophene group, abenzosilole group, a fluorene group, a carbazole group, a dibenzofurangroup, a dibenzothiophene group, or a dibenzosilole group.

In an exemplary embodiment, ring A₄₁ to ring A₄₄ may each independentlybe a benzene group, a fluorene group, a carbazole group, a dibenzofurangroup, a dibenzothiophene group, or a dibenzosilole group, wherein ringA₄₁, ring A₄₂, or a combination thereof may be a benzene group, and ringA₄₃, ring A₄₄, or a combination thereof may be a benzene group.

In Formulae H-1(1) to H-1(3),

X₄₁ may be N-[(L₄₁₁)_(c411)-Z₄₁₁], C(Z₄₁₅)(Z₄₁₆), O, or S,

X₄₂ may be a single bond, N-[(L₄₁₂)_(c412)-Z₄₁₂], C(Z₄₁₇)(Z₄₁₈), O, orS,

X₄₃ may be N-[(L₄₁₃)_(c413)-Z₄₁₃], C(Z₄₁₉)(Z₄₂₀), O, or S, and

X₄₄ may be a single bond, N-[(L₄₁₄)_(c414)-Z₄₁₄], C(Z₄₂₁)(Z₄₂₂), O, orS.

L₄₀₁ and L₄₁₁ to L₄₁₄ may each independently be:

a single bond; or

a π electron-depleted nitrogen-free cyclic group unsubstituted orsubstituted with deuterium, a C₁-C₂₀ alkyl group, a C₁-C₂₀ alkoxy group,a phenyl group, a naphthyl group, a fluorenyl group, a carbazolyl group,a dibenzofuranyl group, a dibenzothiophenyl group, a triphenylenylgroup, a biphenyl group, a terphenyl group, a tetraphenyl group, a(C₁-C₂₀ alkyl)phenyl group, —Si(Q₄₀₁)(Q₄₀₂)(Q₄₀₃), or any combinationthereof (for example, a benzene group, a heptalene group, an indenegroup, a naphthalene group, an azulene group, a heptalene group, anindacene group, acenaphthylene group, a fluorene group, aspiro-bifluorene group, a benzofluorene group, a dibenzofluorene group,a phenalene group, a phenanthrene group, an anthracene group, afluoranthene group, a triphenylene group, a pyrene group, a chrysenegroup, a naphthacene group, a picene group, a perylene group, apentacene group, a hexacene group, a pentaphene group, a rubicene group,a coronene group, an ovalene group, a pyrrole group, an isoindole group,an indole group, a furan group, a thiophene group, a benzofuran group, abenzothiophene group, a benzosilole group, a benzocarbazole group, adibenzocarbazole group, a dibenzofuran group, a dibenzothiophene group,a dibenzothiophene sulfone group, a carbazole group, a dibenzosilolegroup, an indenocarbazole group, an indolocarbazole group, abenzofurocarbazole group, a benzothienocarbazole group, abenzosilolocarbazole group, a triindolobenzene group, an acridine group,or a dihydroacridine group, each unsubstituted or substituted withdeuterium, a C₁-C₁₀ alkyl group, a C₁-C₁₀ alkoxy group, a phenyl group,a naphthyl group, a fluorenyl group, a carbazolyl group, adibenzofuranyl group, a dibenzothiophenyl group, a triphenylenyl group,a biphenyl group, a terphenyl group, a tetraphenyl group,—Si(Q₄₀₁)(Q₄₀₂)(Q₄₀₃), or any combination thereof).

a401 and c411 to c414 each indicate the number of L₄₀₁ and the number ofeach of L₄₁₁ to L₄₁₄, respectively, and may each independently be aninteger from 1 to 10 (for example, an integer from 1 to 5), wherein,when a401 is two or more, two or more L₄₀₁ may be identical to ordifferent from each other, when c411 is two or more, two or more L₄₁₁may be identical to or different from each other, when c412 is two ormore, two or more L₄₁₂ may be identical to or different from each other,when c413 is two or more, two or more L₄₁₃ may be identical to ordifferent from each other, and when c414 is two or more, two or moreL₄₁₄ may be identical to or different from each other.

Z₄₁ to Z₄₄ and Z₄₁₁ to Z₄₂₂ may each independently be:

hydrogen, deuterium, a C₁-C₂₀ alkyl group, or a C₁-C₂₀ alkoxy group; or

a π electron-depleted nitrogen-free cyclic group unsubstituted orsubstituted with deuterium, a C₁-C₂₀ alkyl group, a C₁-C₂₀ alkoxy group,a phenyl group, a naphthyl group, a fluorenyl group, a carbazolyl group,a dibenzofuranyl group, a dibenzothiophenyl group, a triphenylenylgroup, a biphenyl group, a terphenyl group, a tetraphenyl group, a(C₁-C₂₀ alkyl)phenyl group, —Si(Q₄₀₁)(Q₄₀₂)(Q₄₀₃), or any combinationthereof (for example, a phenyl group, a biphenyl group, a terphenylgroup, a tetraphenyl group, a naphthyl group, a fluorenyl group, aspiro-bifluorenyl group, a benzofluorenyl group, a dibenzofluorenylgroup, a phenanthrenyl group, an anthracenyl group, a triphenylenylgroup, a pyrenyl group, a chrysenyl group, a pyrrolyl group, anisoindolyl group, an indolyl group, a furanyl group, a thiophenyl group,a benzofuranyl group, a benzothiophenyl group, a benzosilolyl group, abenzocarbazolyl group, a dibenzocarbazolyl group, a dibenzofuranylgroup, a dibenzothiophenyl group, a carbazolyl group, a dibenzosilolylgroup, an indeno carbazolyl group, an indolocarbazolyl group, abenzofurocarbazolyl group, a benzothienocarbazolyl group, abenzosilolocarbazolyl group, an acridinyl group or a dihydroacridinylgroup, each unsubstituted or substituted with deuterium, a C₁-C₁₀ alkylgroup, a C₁-C₁₀ alkoxy group, a phenyl group, a naphthyl group, afluorenyl group, a carbazolyl group, a dibenzofuranyl group, adibenzothiophenyl group, a triphenylenyl group, a biphenyl group, aterphenyl group, a tetraphenyl group, —Si(Q₄₀₁)(Q₄₀₂)(Q₄₀₃), or anycombination thereof).

b41 to b44 each indicate the number of Z₄₁ to the number of Z₄₄,respectively, and may each independently be 1, 2, 3, or 4.

Q₄₀₁ to Q₄₀₃ may each independently be hydrogen, deuterium, a C₁-C₂₀alkyl group, a C₁-C₂₀ alkoxy group, a phenyl group, a naphthyl group, afluorenyl group, a carbazolyl group, a dibenzofuranyl group, adibenzothiophenyl group, a triphenylenyl group, a biphenyl group, aterphenyl group, or a tetraphenyl group.

In one embodiment, in Formulae H-1(1) to H-1(3),

L₄₀₁ and L₄₁₁ to L₄₁₄ may each independently be:

a single bond; or

a benzene group, a fluorene group, a dibenzofuran group, adibenzothiophene group, a carbazole group, a dibenzosilole group, anindenocarbazole group, an indolocarbazole group, a benzofurocarbazolegroup, a benzothienocarbazole group, a benzosilolocarbazole group, anacridine group, or a dihydroacridine group, each unsubstituted orsubstituted with deuterium, a C₁-C₁₀ alkyl group, a C₁-C₁₀ alkoxy group,a phenyl group, a naphthyl group, a fluorenyl group, a carbazolyl group,a dibenzofuranyl group, a dibenzothiophenyl group, a triphenylenylgroup, a biphenyl group, a terphenyl group, a tetraphenyl group, a(C₁-C₁₀ alkyl)phenyl group, or any combination thereof,

Z₄₁ to Z₄₄ and Z₄₁₁ to Z₄₂₂ may each independently be:

hydrogen, deuterium, a C₁-C₁₀ alkyl group, or a C₁-C₁₀ alkoxy group; or

a phenyl group, a biphenyl group, a terphenyl group, a tetraphenylgroup, a fluorenyl group, a dibenzocarbazolyl group, a dibenzofuranylgroup, a dibenzothiophenyl group, a carbazolyl group, a dibenzosilolylgroup, an indeno carbazolyl group, an indolocarbazolyl group, abenzofurocarbazolyl group, a benzothienocarbazolyl group, abenzosilolocarbazolyl group, an acridinyl group, or a dihydroacridinylgroup, each unsubstituted or substituted with deuterium, a C₁-C₁₀ alkylgroup, a C₁-C₁₀ alkoxy group, a phenyl group, a naphthyl group, afluorenyl group, a carbazolyl group, a dibenzofuranyl group, adibenzothiophenyl group, a triphenylenyl group, a biphenyl group, aterphenyl group, a tetraphenyl group, a (C₁-C₁₀ alkyl)phenyl group, orany combination thereof but embodiments of the present disclosure arenot limited thereto.

In one embodiment, the first material may include at least one ofCompounds H1 to H32, but embodiments of the present disclosure are notlimited thereto:

In one embodiment, the first material may not be an amine compound.

In one or more embodiments, the first material may not be1,3-bis(9-carbazolyl)benzene (mCP), tris(4-carbazoyl-9-ylphenyl)amine(TCTA), 4,4′-bis(N-carbazolyl)-1,1′-biphenyl (CBP),3,3-bis(carbazol-9-yl)biphenyl (mCBP),N,N′-di(1-naphthyl)-N,N′-diphenyl-(1,1′-biphenyl)-4,4′-diamine (NPB),4,4′,4″-tris[phenyl(m-tolyl)amino]triphenylamine (m-MTDATA), orN,N′-bis(3-methylphenyl)-N,N′-diphenylbenzidine (TPD).

FIGURE is a schematic view of an organic light-emitting device 10according to an embodiment. Hereinafter, the structure of an organiclight-emitting device according to an embodiment and a method ofmanufacturing an organic light-emitting device according to anembodiment will be described in connection with the FIGURE. The organiclight-emitting device 10 includes a first electrode 11, an organic layer15, and a second electrode 19, which are sequentially stacked.

A substrate may be additionally disposed under the first electrode 11 orabove the second electrode 19. For use as the substrate, any substratethat is used in organic light-emitting devices may be used, and thesubstrate may be a glass substrate or a transparent plastic substrate,each having excellent mechanical strength, thermal stability,transparency, surface smoothness, ease of handling, and waterresistance.

The first electrode 11 may be formed by depositing or sputtering amaterial for forming the first electrode 11 on the substrate. The firstelectrode 11 may be an anode. The material for forming the firstelectrode 11 may be a material with a high work function to facilitatehole injection. The first electrode 11 may be a reflective electrode, asemi-transmissive electrode, or a transmissive electrode. The materialfor forming the first electrode may be, for example, indium tin oxide(ITO), indium zinc oxide (IZO), tin oxide (SnO₂), or zinc oxide (ZnO).In one or more embodiments, magnesium (Mg), aluminum (Al),aluminum-lithium (Al—Li), calcium (Ca), magnesium-indium (Mg—In), ormagnesium-silver (Mg—Ag) may be used as the material for forming thefirst electrode.

The first electrode 11 may have a single-layered structure or amulti-layered structure including two or more layers. In an exemplaryembodiment, the first electrode 11 may have a three-layered structure ofITO/Ag/ITO, but the structure of the first electrode 110 is not limitedthereto.

The organic layer 15 is disposed on the first electrode 11.

The organic layer 15 may include a hole transport region, an emissionlayer, and an electron transport region.

The hole transport region may be disposed between the first electrode 11and the emission layer.

The hole transport region may include a hole injection layer, a holetransport layer, an electron blocking layer, a buffer layer, or anycombination thereof.

The hole transport region may include either a hole injection layer or ahole transport layer. In one or more embodiments, the hole transportregion may have a hole injection layer/hole transport layer structure ora hole injection layer/hole transport layer/electron blocking layerstructure, which are sequentially stacked in this stated order from thefirst electrode 11.

A hole injection layer may be formed on the first electrode 11 by usingone or more suitable methods such as vacuum deposition, spin coating,casting, or Langmuir-Blodgett (LB) deposition.

When a hole injection layer is formed by vacuum deposition, thedeposition conditions may vary according to a compound that is used toform the hole injection layer, and the structure and thermalcharacteristics of the hole injection layer. In an exemplary embodiment,the deposition conditions may include a deposition temperature of about100° C. to about 500° C., a vacuum pressure of about 10⁻⁸ torr to about10⁻³ torr, and a deposition rate of about 0.01 Å/sec to about 100 Å/sec.However, the deposition conditions are not limited thereto.

When the hole injection layer is formed using spin coating, coatingconditions may vary according to the material used to form the holeinjection layer, and the structure and thermal properties of the holeinjection layer. In an exemplary embodiment, a coating speed may be fromabout 2,000 rpm to about 5,000 rpm, and a temperature at which a heattreatment is performed to remove a solvent after coating may be fromabout 80° C. to about 200° C. However, the coating conditions are notlimited thereto.

Conditions for forming a hole transport layer and an electron blockinglayer may be understood by referring to conditions for forming the holeinjection layer.

The hole transport region may include m-MTDATA, TDATA, 2-TNATA, NPB,β-NPB, TPD, Spiro-TPD, Spiro-NPB, methylated-NPB, TAPC, HMTPD,4,4′,4″-tris(N-carbazolyl)triphenylamine (TCTA),polyaniline/dodecylbenzenesulfonic acid (PANI/DBSA),poly(3,4-ethylenedioxythiophene)/poly(4-styrenesulfonate) (PEDOT/PSS),polyaniline/camphor sulfonic acid (PANI/CSA),polyaniline/poly(4-styrenesulfonate) (PANI/PSS), a compound representedby Formula 201 below, a compound represented by Formula 202, or acombination thereof:

In Formula 201, Ar₁₀₁ and Ar₁₀₂ may each independently be:

a phenylene group, a pentalenylene group, an indenylene group, anaphthylene group, an azulenylene group, a heptalenylene group, anacenaphthylene group, a fluorenylene group, a phenalenylene group, aphenanthrenylene group, an anthracenylene group, a fluoranthenylenegroup, a triphenylenylene group, a pyrenylene group, a chrysenylenylenegroup, a naphthacenylene group, a picenylene group, a perylenylenegroup, or a pentacenylene group; or

a phenylene group, a pentalenylene group, an indenylene group, anaphthylene group, an azulenylene group, a heptalenylene group, anacenaphthylene group, a fluorenylene group, a phenalenylene group, aphenanthrenylene group, an anthracenylene group, a fluoranthenylenegroup, a triphenylenylene group, a pyrenylene group, a chrysenylenylenegroup, a naphthacenylene group, a picenylene group, a perylenylenegroup, or a pentacenylene group, each substituted with deuterium, —F,—Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, an aminogroup, an amidino group, a hydrazine group, a hydrazone group, acarboxylic acid group or a salt thereof, a sulfonic acid group or a saltthereof, a phosphoric acid group or a salt thereof, a C₁-C₆₀ alkylgroup, a C₂-C₆₀ alkenyl group, a C₂-C₆₀ alkynyl group, a C₁-C₆₀ alkoxygroup, a C₃-C₁₀ cycloalkyl group, a C₃-C₁₀ cycloalkenyl group, a C₂-C₁₀heterocycloalkyl group, a C₂-C₁₀ heterocycloalkenyl group, a C₆-C₆₀ arylgroup, a C₆-C₆₀ aryloxy group, a C₆-C₆₀ arylthio group, a C₁-C₆₀heteroaryl group, a monovalent non-aromatic condensed polycyclic group,a monovalent non-aromatic condensed heteropolycyclic group, or anycombination thereof.

In Formula 201, xa and xb may each independently be an integer from 0 to5, or may be 0, 1, or 2. In an exemplary embodiment, xa is 1 and xb is0, but xa and xb are not limited thereto.

In Formulae 201 and 202, R₁₀₁ to R₁₀₈, R₁₁₁ to R₁₁₉, and R₁₂₁ to R₁₂₄may each independently be:

hydrogen, deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group,a nitro group, an amino group, an amidino group, a hydrazine group, ahydrazone group, a carboxylic acid group or a salt thereof, a sulfonicacid group or a salt thereof, a phosphoric acid group or a salt thereof,a C₁-C₁₀ alkyl group (for example, a methyl group, an ethyl group, apropyl group, a butyl group, a pentyl group, a hexyl group, and so on),or a C₁-C₁₀ alkoxy group (for example, a methoxy group, an ethoxy group,a propoxy group, a butoxy group, a pentoxy group, and so on);

a C₁-C₁₀ alkyl group or a C₁-C₁₀ alkoxy group, each substituted withdeuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitrogroup, an amino group, an amidino group, a hydrazine group, a hydrazonegroup, a carboxylic acid group or a salt thereof, a sulfonic acid groupor a salt thereof, and a phosphoric acid group or a salt thereof, or anycombination thereof;

a phenyl group, a naphthyl group, an anthracenyl group, a fluorenylgroup, or a pyrenyl group; or

a phenyl group, a naphthyl group, an anthracenyl group, a fluorenylgroup, or a pyrenyl group, each substituted with deuterium, —F, —Cl,—Br, —I, a hydroxyl group, a cyano group, a nitro group, an amino group,an amidino group, a hydrazine group, a hydrazone group, a carboxylicacid group or a salt thereof, a sulfonic acid group or a salt thereof, aphosphoric acid group or a salt thereof, a C₁-C₁₀ alkyl group, a C₁-C₁₀alkoxy group, or any combination thereof, but embodiments of the presentdisclosure are not limited thereto.

In Formula 201, R₁₀₉ may be:

a phenyl group, a naphthyl group, an anthracenyl group, or a pyridinylgroup; or

a phenyl group, a naphthyl group, an anthracenyl group, or a pyridinylgroup, each substituted with deuterium, —F, —Cl, —Br, —I, a hydroxylgroup, a cyano group, a nitro group, an amino group, an amidino group, ahydrazine group, a hydrazone group, a carboxylic acid group or a saltthereof, a sulfonic acid group or a salt thereof, a phosphoric acidgroup or a salt thereof, a C₁-C₂₀ alkyl group, a C₁-C₂₀ alkoxy group, aphenyl group, a naphthyl group, an anthracenyl group, a pyridinyl group,or any combination thereof.

According to an embodiment, the compound represented by Formula 201 maybe represented by Formula 201A, but embodiments of the presentdisclosure are not limited thereto:

In Formula 201A, R₁₀₁, R₁₁₁, R₁₁₂, and R₁₀₉ are each independently thesame as described herein.

In an exemplary embodiment, the compound represented by Formula 201 andthe compound represented by Formula 202 may include Compounds HT1 toHT20, but embodiments of the present disclosure are not limited thereto:

A thickness of the hole transport region may be in a range of about 100Å to about 10,000 Å, for example, about 100 Å to about 1,000 Å. When thehole transport region includes a hole injection layer and a holetransport layer, the thickness of the hole injection layer may be in arange of about 100 Å to about 10,000 Å, and for example, about 100 Å toabout 1,000 Å, and the thickness of the hole transport layer may be in arange of about 50 Å to about 2,000 Å, and for example, about 100 Å toabout 1,500 Å. When the thicknesses of the hole transport region, thehole injection layer, and the hole transport layer are within theseranges, satisfactory hole transporting characteristics may be obtainedwithout a substantial increase in driving voltage.

The hole transport region may further include, in addition to thesematerials, a charge-generation material for the improvement ofconductive properties. The charge-generation material may behomogeneously or non-homogeneously dispersed in the hole transportregion.

The charge-generation material may be, for example, a p-dopant. Thep-dopant may be a quinone derivative, a metal oxide, or a cyanogroup-containing compound, but embodiments of the present disclosure arenot limited thereto. Non-limiting examples of the p-dopant are a quinonederivative, such as tetracyanoquinonedimethane (TCNQ) or2,3,5,6-tetrafluoro-tetracyano-1,4-benzoquinonedimethane (F4-TCNQ); ametal oxide, such as a tungsten oxide or a molybdenum oxide; and a cyanogroup-containing compound, such as Compound HT-D1 or Compound HT-D2below, but are not limited thereto:

The hole transport region may include a buffer layer.

Also, the buffer layer may compensate for an optical resonance distanceaccording to a wavelength of light emitted from the emission layer, andthus, efficiency of a formed organic light-emitting device may beimproved.

The electron transport region may further include an electron blockinglayer. The electron blocking layer may include, for example, mCP, but amaterial therefor is not limited thereto:

Then, an emission layer may be formed on the hole transport region byvacuum deposition, spin coating, casting, LB deposition, or the like.When the emission layer is formed by vacuum deposition or spin coating,the deposition or coating conditions may be similar to those applied informing the hole injection layer although the deposition or coatingconditions may vary according to a compound that is used to form theemission layer.

When the organic light-emitting device is a full-color organiclight-emitting device, the emission layer may be patterned into a redemission layer, a green emission layer, and/or a blue emission layer. Inone or more embodiments, due to a stacked structure including a redemission layer, a green emission layer, and/or a blue emission layer,the emission layer may emit white light.

The emission layer may include the host and the thermally activateddelayed fluorescence emitter, wherein the host and the thermallyactivated delayed fluorescence emitter are each independently the sameas described herein.

A thickness of the emission layer may be in a range of about 100 Å toabout 1,000 Å, for example, about 200 Å to about 600 Å. When thethickness of the emission layer is within this range, excellentlight-emission characteristics may be obtained without a substantialincrease in driving voltage.

Then, an electron transport region may be disposed on the emissionlayer.

The electron transport region may include a hole blocking layer, anelectron transport layer, an electron injection layer, or anycombination thereof.

In an exemplary embodiment, the electron transport region may have ahole blocking layer/electron transport layer/electron injection layerstructure or an electron transport layer/electron injection layerstructure, but the structure of the electron transport region is notlimited thereto. The electron transport layer may have a single-layeredstructure or a multi-layered structure including two or more differentmaterials.

Conditions for forming the hole blocking layer, the electron transportlayer, and the electron injection layer which constitute the electrontransport region may be understood by referring to the conditions forforming the hole injection layer.

When the electron transport region includes a hole blocking layer, thehole blocking layer may include, for example, BCP, Bphen, or anycombination thereof, but may also include other materials:

A thickness of the hole blocking layer may be in a range of about 20 Åto about 1,000 Å, for example, about 30 Å to about 300 Å. When thethickness of the hole blocking layer is within these ranges, the holeblocking layer may have improved hole blocking ability without asubstantial increase in driving voltage.

The electron transport layer may further include BCP, Bphen, Alq₃, BAlq,TAZ, NTAZ, or any combination thereof:

In one or more embodiments, the electron transport layer may include acompound of ET1 to ET25, but are not limited thereto:

A thickness of the electron transport layer may be in a range of about100 Å to about 1,000 Å, for example, about 150 Å to about 500 Å. Whenthe thickness of the electron transport layer is within the rangedescribed above, the electron transport layer may have satisfactoryelectron transport characteristics without a substantial increase indriving voltage.

Also, the electron transport layer may further include, in addition tothe materials described above, a metal-containing material.

The metal-containing material may include a Li complex. The Li complexmay include, for example, Compound ET-D1 (lithium quinolate, LiQ) orET-D2:

The electron transport region may include an electron injection layerthat promotes the flow of electrons from the second electrode 19thereinto.

The electron injection layer may include LiF, NaCl, CsF, Li₂O, BaO, orany combination thereof.

A thickness of the electron injection layer may be in a range of about 1Å to about 100 Å, for example, about 3 Å to about 90 Å. When thethickness of the electron injection layer is within the range describedabove, the electron injection layer may have satisfactory electroninjection characteristics without a substantial increase in drivingvoltage.

The second electrode 19 is disposed on the organic layer 15. The secondelectrode 19 may be a cathode. A material for forming the secondelectrode 19 may be a metal, an alloy, an electrically conductivecompound, or a combination thereof, which have a relatively low workfunction. In an exemplary embodiment, lithium (Li), magnesium (Mg),aluminum (Al), aluminum-lithium (Al—Li), calcium (Ca), magnesium-indium(Mg—In), or magnesium-silver (Mg—Ag) may be used as a material forforming the second electrode 19. In one or more embodiments, tomanufacture a top-emission type light-emitting device, a transmissiveelectrode formed using ITO or IZO may be used as the second electrode19.

Hereinbefore, the organic light-emitting device has been described withreference to FIG. 1, but embodiments of the present disclosure are notlimited thereto.

The term “C₁-C₆₀ alkyl group” as used herein refers to a linear orbranched saturated aliphatic hydrocarbon monovalent group having 1 to 60carbon atoms, and non-limiting examples thereof include a methyl group,an ethyl group, a propyl group, an isobutyl group, a sec-butyl group, atert-butyl group, a pentyl group, an isoamyl group, and a hexyl group.The term “C₁-C₆₀ alkylene group” as used herein refers to a divalentgroup having the same structure as the C₁-C₆₀ alkyl group.

The term “C₁-C₆₀ alkoxy group” as used herein refers to a monovalentgroup represented by —OA₁₀₁ (wherein A₁₀₁ is the C₁-C₆₀ alkyl group),and non-limiting examples thereof include a methoxy group, an ethoxygroup, and an isopropyloxy group.

The term “C₂-C₆₀ alkenyl group” as used herein refers to a hydrocarbongroup formed by substituting at least one carbon-carbon double bond inthe middle or at the terminus of the C₂-C₆₀ alkyl group, and examplesthereof include an ethenyl group, a propenyl group, and a butenyl group.The term “C₂-C₆₀ alkenylene group” as used herein refers to a divalentgroup having the same structure as the C₂-C₆₀ alkenyl group.

The term “C₂-C₆₀ alkynyl group” as used herein refers to a hydrocarbongroup formed by substituting at least one carbon-carbon triple bond inthe middle or at the terminus of the C₂-C₆₀ alkyl group, and examplesthereof include an ethynyl group, and a propynyl group. The term “C₂-C₆₀alkynylene group” as used herein refers to a divalent group having thesame structure as the C₂-C₆₀ alkynyl group.

The term “C₃-C₁₀ cycloalkyl group” as used herein refers to a monovalentsaturated hydrocarbon monocyclic group having 3 to 10 carbon atoms, andnon-limiting examples thereof include a cyclopropyl group, a cyclobutylgroup, a cyclopentyl group, a cyclohexyl group, and a cycloheptyl group.The term “C₃-C₁₀ cycloalkylene group” as used herein refers to adivalent group having the same structure as the C₃-C₁₀ cycloalkyl group.

The term “C₂-C₁₀ heterocycloalkyl group” as used herein refers to amonovalent saturated monocyclic group having N, O, P, Si, Se or S as aring-forming atom and 2 to 10 carbon atoms, and non-limiting examplesthereof include a tetrahydrofuranyl group and a tetrahydrothiophenylgroup. The term “C₂-C₁₀ heterocycloalkylene group” as used herein refersto a divalent group having the same structure as the C₂-C₁₀heterocycloalkyl group.

The term “C₃-C₁₀ cycloalkenyl group” as used herein refers to amonovalent monocyclic group that has 3 to 10 carbon atoms and acarbon-carbon double bond in the ring thereof and no aromaticity, andnon-limiting examples thereof include a cyclopentenyl group, acyclohexenyl group, and a cycloheptenyl group. The term “C₃-C₁₀cycloalkenylene group” as used herein refers to a divalent group havingthe same structure as the C₃-C₁₀ cycloalkenyl group.

The term “C₂-C₁₀ heterocycloalkenyl group” as used herein refers to amonovalent monocyclic group that has N, O, P, Si, Se, or S as aring-forming atom, 2 to 10 carbon atoms, and at least one carbon-carbondouble bond in its ring. Non-limiting examples of the C₂-C₁₀heterocycloalkenyl group include a 2,3-dihydrofuranyl group, and a2,3-dihydrothiophenyl group. The term “C₂-C₁₀ heterocycloalkenylenegroup” as used herein refers to a divalent group having the samestructure as the C₂-C₁₀ heterocycloalkenyl group.

The term “C₆-C₆₀ aryl group” as used herein refers to a monovalent grouphaving a carbocyclic aromatic system having 6 to 60 carbon atoms, andthe term “C₆-C₆₀ arylene group” as used herein refers to a divalentgroup having a carbocyclic aromatic system having 6 to 60 carbon atoms.Non-limiting examples of the C₆-C₆₀ aryl group include a phenyl group, anaphthyl group, an anthracenyl group, a phenanthrenyl group, a pyrenylgroup, and a chrysenyl group. When the C₆-C₆₀ aryl group and the C₆-C₆₀arylene group each include two or more rings, the rings may be fused toeach other.

The term “C₂-C₆₀ heteroaryl group” as used herein refers to a monovalentgroup having a heterocyclic aromatic system that has N, O, P, Si, Se, orS as a ring-forming atom, and 2 to 60 carbon atoms. The term “C₂-C₆₀heteroarylene group,” as used herein refers to a divalent group having aheterocyclic aromatic system that has an N, O, P, Si, Se, or S as aring-forming atom, and 2 to 60 carbon atoms. Non-limiting examples ofthe C₂-C₆₀ heteroaryl group include a pyridinyl group, a pyrimidinylgroup, a pyrazinyl group, a pyridazinyl group, a triazinyl group, aquinolinyl group, and an isoquinolinyl group. When the C₂-C₆₀ heteroarylgroup and the C₂-C₆₀ heteroarylene group each include two or more rings,the rings may be fused to each other.

The term “C₆-C₆₀ aryloxy group” as used herein refers to —OA₁₀₂ (whereinA₁₀₂ is the C₆-C₆₀ aryl group), and a C₆-C₆₀ arylthio group used hereinindicates —SA103 (wherein A₁₀₃ is the C₆-C₆₀ aryl group).

The term “monovalent non-aromatic condensed polycyclic group” as usedherein refers to a monovalent group having two or more rings condensedto each other, only carbon atoms (for example, the number of carbonatoms may be in a range of 8 to 60) as ring-forming atoms, and noaromaticity in its entire molecular structure. Non-limiting examples ofthe monovalent non-aromatic condensed polycyclic group include afluorenyl group. The term “divalent non-aromatic condensed polycyclicgroup” as used herein refers to a divalent group having the samestructure as the monovalent non-aromatic condensed polycyclic group.

The term “monovalent non-aromatic condensed heteropolycyclic group” asused herein refers to a monovalent group having two or more ringscondensed to each other, an N, O, P, Si, Se, or S, other than carbonatoms (for example, the number of carbon atoms may be in a range of 2 to60), as ring-forming atoms, and no aromaticity in its entire molecularstructure. Non-limiting examples of the monovalent non-aromaticcondensed heteropolycyclic group include a carbazolyl group. The term“divalent non-aromatic condensed heteropolycyclic group” as used hereinrefers to a divalent group having the same structure as the monovalentnon-aromatic condensed heteropolycyclic group.

In the present specification, a substituent of the substituted C₁-C₆₀alkyl group, the substituted C₂-C₆₀ alkenyl group, the substitutedC₂-C₆₀ alkynyl group, the substituted C₁-C₆₀ alkoxy group, thesubstituted C₃-C₁₀ cycloalkyl group, the substituted C₂-C₁₀heterocycloalkyl group, the substituted C₃-C₁₀ cycloalkenyl group, thesubstituted C₂-C₁₀ heterocycloalkenyl group, the substituted C₆-C₆₀ arylgroup, the substituted C₆-C₆₀ aryloxy group, the substituted C₆-C₆₀arylthio group, the substituted C₁-C₆₀ heteroaryl group, the substitutedmonovalent non-aromatic condensed polycyclic group, and the substitutedmonovalent non-aromatic condensed heteropolycyclic group may be:

deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitrogroup, an amino group, an amidino group, a hydrazine group, a hydrazonegroup, a carboxylic acid group or a salt thereof, a sulfonic acid groupor a salt thereof, a phosphoric acid group or a salt thereof, a C₁-C₆₀alkyl group, a C₂-C₆₀ alkenyl group, a C₂-C₆₀ alkynyl group, or a C₁-C₆₀alkoxy group;

a C₁-C₆₀ alkyl group, a C₂-C₆₀ alkenyl group, a C₂-C₆₀ alkynyl group, ora C₁-C₆₀ alkoxy group, each substituted with deuterium, —F, —Cl, —Br,—I, a hydroxyl group, a cyano group, a nitro group, an amino group, anamidino group, a hydrazine group, a hydrazone group, a carboxylic acidgroup or a salt thereof, a sulfonic acid group or a salt thereof, aphosphoric acid group or a salt thereof, a C₃-C₁₀ cycloalkyl group, aC₂-C₁₀ heterocycloalkyl group, a C₃-C₁₀ cycloalkenyl group, a C₂-C₁₀heterocycloalkenyl group, a C₆-C₆₀ aryl group, a C₆-C₆₀ aryloxy group, aC₆-C₆₀ arylthio group, a C₁-C₆₀ heteroaryl group, a monovalentnon-aromatic condensed polycyclic group, a monovalent non-aromaticcondensed heteropolycyclic group, —Si(Q₁₁)(Q₁₂)(Q₁₃), —N(Q₁₄)(Q₁₅),—B(Q₁₆)(Q₁₇), or any combination thereof;

a C₃-C₁₀ cycloalkyl group, a C₂-C₁₀ heterocycloalkyl group, a C₃-C₁₀cycloalkenyl group, a C₂-C₁₀ heterocycloalkenyl group, a C₆-C₆₀ arylgroup, a C₆-C₆₀ aryloxy group, a C₆-C₆₀ arylthio group, a C₁-C₆₀heteroaryl group, a monovalent non-aromatic condensed polycyclic group,or a monovalent non-aromatic condensed heteropolycyclic group;

a C₃-C₁₀ cycloalkyl group, a C₂-C₁₀ heterocycloalkyl group, a C₃-C₁₀cycloalkenyl group, a C₂-C₁₀ heterocycloalkenyl group, a C₆-C₆₀ arylgroup, a C₆-C₆₀ aryloxy group, a C₆-C₆₀ arylthio group, a C₁-C₆₀heteroaryl group, a monovalent non-aromatic condensed polycyclic group,or a monovalent non-aromatic condensed heteropolycyclic group, eachsubstituted with deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyanogroup, a nitro group, an amino group, an amidino group, a hydrazinegroup, a hydrazone group, a carboxylic acid group or a salt thereof, asulfonic acid group or a salt thereof, a phosphoric acid group or a saltthereof, a C₁-C₆₀ alkyl group, a C₂-C₆₀ alkenyl group, a C₂-C₆₀ alkynylgroup, a C₁-C₆₀ alkoxy group, a C₃-C₁₀ cycloalkyl group, a C₂-C₁₀heterocycloalkyl group, a C₃-C₁₀ cycloalkenyl group, a C₂-C₁₀heterocycloalkenyl group, a C₆-C₆₀ aryl group, a C₆-C₆₀ aryloxy group, aC₆-C₆₀ arylthio group, a C₁-C₆₀ heteroaryl group, a monovalentnon-aromatic condensed polycyclic group, a monovalent non-aromaticcondensed heteropolycyclic group, —Si(Q₂₁)(Q₂₂)(Q₂₃), —N(Q₂₄)(Q₂₅),—B(Q₂₆)(Q₂₇), or any combination thereof; or

—Si(Q₃₁)(Q₃₂)(Q₃₃), —N(Q₃₄)(Q₃₅), or —B(Q₃₆)(Q₃₇), and

Q₁ to Q₇, Q₁₁ to Q₁₇, Q₂₁ to Q₂₇, and Q₃₁ to Q₃₇ may each independentlybe hydrogen, a substituted or unsubstituted C₁-C₆₀ alkyl group, asubstituted or unsubstituted C₂-C₆₀ alkenyl group, a substituted orunsubstituted C₂-C₆₀ alkynyl group, a substituted or unsubstitutedC₁-C₆₀ alkoxy group, a substituted or unsubstituted C₃-C₁₀ cycloalkylgroup, a substituted or unsubstituted C₂-C₁₀ heterocycloalkyl group, asubstituted or unsubstituted C₃-C₁₀ cycloalkenyl group, a substituted orunsubstituted C₂-C₁₀ heterocycloalkenyl group, a substituted orunsubstituted C₆-C₆₀ aryl group, a substituted or unsubstituted C₆-C₆₀aryloxy group, a substituted or unsubstituted C₆-C₆₀ arylthio group, asubstituted or unsubstituted C₁-C₆₀ heteroaryl group, a substituted orunsubstituted monovalent non-aromatic condensed polycyclic group, or asubstituted or unsubstituted monovalent non-aromatic condensedheteropolycyclic group.

The term “room temperature” as used herein refers to about 25° C.

The term “a biphenyl group, a terphenyl group, or a tetraphenyl group”as used herein each refer to a monovalent group linked to two, three, orfour benzene groups, respectively, via a single bond.

Hereinafter, a compound and an organic light-emitting device accordingto embodiments are described in detail with reference to SynthesisExample and Examples. However, the organic light-emitting device is notlimited thereto. The wording “B was used instead of A” used indescribing Synthesis Examples means that an amount of A used wasidentical to an amount of B used, in terms of a molar equivalent.

EXAMPLES Synthesis Example 1 Synthesis of Compound EH1

Synthesis of Intermediate EH1(1)

In a 500 ml round-bottom flask in a water bath at room temperature, 8.8g (46 mmol) of 3-cyanide carbazole (Compound I-1) was mixed with 250 mlof N,N-dimethylformamide (DMF), and 1.84 g (46 mmol, 1 eq) of 60 wt %sodium hydride (NaH) in mineral oil was slowly added to the mixedsolution at room temperature (resulting in the production of hydrogen).Afterwards, the resulting mixed solution was stirred at room temperaturefor 15 minutes, and then, 11.0 g (55 mmol, ˜1.2 eq) of Compound I-2 wasadded thereto at once. The temperature was slowly raised up to 80° C.,and the resulting mixed solution was stirred overnight. The temperatureof the mixed solution thus obtained was cooled to room temperature, andexcess water was poured into the mixture to precipitate a solid product.50 ml of ethyl acetate was added to the mixed solution which was thenstirred. A solid product obtained by filtration was washed with 50 ml ofethyl acetate, and a resulting product obtained therefrom was driedwithout further purification, thereby obtaining 12 g (purity of 99.88%by LC-MS) of a white solid product, Intermediate EH1(1).

Synthesis of Compound EH1

16 g (43 mmol, 1 eq) of Intermediate EH1(1), 31.7 g (86 mmol, 2 eq) ofCompound I-3, 23.8 g (172 mmol, 4 eq) of potassium carbonate (K₂CO₃),and 2.3 g (2 mmol, 0.05 eq) of Pd(PPh₃)₄ were added to a mixed solutionof 110 ml of tetrahydrofuran (THF) and 85 ml of water, and the resultingmixed solution was stirred at a temperature of 85° C. overnight (byusing a pressure reactor). The mixed solution thus obtained was cooledto room temperature, and the reaction mixture was extracted with ethylacetate. The resulting organic layer was dried by using MgSO₄, filtered,and concentrated in vacuo to remove the solvent. A resulting productobtained therefrom was separated and purified by silica gel columnchromatography, thereby obtaining 13 g of Compound EH1 (purity of 99.95%by LC-MS).

LC-Mass Cal.: 534.18 g/mol, Measured.: M+1=535.18 g/mol

Synthesis Example 2 Synthesis of Compound EH2

Synthesis of Intermediate EH2(1)

In a 500 ml round-bottom flask in a water bath at room temperature, 17.4g (80 mmol) of 3,6-dicyanide carbazole (Compound I-4) was mixed with 200ml of N,N-dimethylformamide (DMF), and 3.6 g (90 mmol, 1 eq) of 60 wt %sodium hydride (NaH) in mineral oil was slowly added to the mixedsolution at room temperature (resulting in the production of hydrogen).Here, 150 ml of N,N-dimethylformamide (DMF) was used to wash out thesolid products attached to a container wall. Afterwards, the mixedsolution containing the washed solid products was stirred for 10 minutesat room temperature, and 20 g (100 mmol, ˜1.25 eq) of Compound I-2 wasadded thereto at once. The temperature was slowly raised up to 80° C.,and the resulting mixed solution was stirred overnight. The mixedsolution thus obtained was cooled to room temperature, and excess waterwas poured into the mixture to precipitate a solid product. 50 ml ofethyl acetate was added to the mixed solution which was then stirred. Asolid product obtained by filtration was washed with 50 ml of ethylacetate, and a resulting product obtained therefrom was dried withoutfurther purification, thereby obtaining 30 g (purity of 99.69%) ofIntermediate EH2(1).

Synthesis of Compound EH2

16 g (40 mmol, 1 eq) of Intermediate EH2(1), 22.2 g (60 mmol, 1.5 eq) ofCompound I-3, 16.8 g (120 mmol, 3 eq) of potassium carbonate (K₂CO₃),and 2.2 g (2 mmol, 0.05 eq) of Pd(PPh₃)₄ were added to a mixed solutionof 300 ml of tetrahydrofuran (THF) and 75 ml of water, and the resultingmixed solution was stirred at a temperature of 85° C. overnight (byusing a pressure reactor). The mixed solution thus obtained was cooledto room temperature, and the reaction mixture was extracted with ethylacetate. The resulting organic layer was dried by using MgSO₄, filtered,and concentrated in vacuo to remove the solvent. A resulting productobtained therefrom was separated and purified by silica gel columnchromatography, thereby obtaining 13 g (purity of 99.90% by LC-MS) ofCompound EH2.

LC-Mass Cal.: 559.18 g/mol, Measured.: M+1=560.18 g/mol

Synthesis Example 3 Synthesis of Compound EH14

Synthesis of Intermediate EH14(1)

In a 500 ml round-bottom flask in a water bath at room temperature, 8.2g (38 mmol) of 3,6-dicyanide carbazole (Compound I-4) was mixed with 150ml of N,N-dimethylformamide (DMF), and 1.5 g (38 mmol, 1 eq) of 60 wt %sodium hydride (NaH) in mineral oil was slowly added to the mixedsolution at room temperature (resulting in the production of hydrogen).Here, 100 ml of N,N-dimethylformamide (DMF) was used to wash out thesolid products attached to a container wall. Afterwards, the mixedsolution containing the washed solid products was stirred for 10 minutesat room temperature, and 9.1 g (45 mmol, ˜1.2 eq) of Compound I-5 wasadded thereto at once. The temperature was slowly raised up to 80° C.,and the resulting mixed solution was stirred overnight. The mixedsolution thus obtained was cooled to room temperature, and excess waterwas poured into the mixture to precipitate a solid product. 50 ml ofethyl acetate was added to the mixed solution which was then stirred. Asolid product obtained by filtration was washed with 50 ml of ethylacetate, and a resulting product obtained therefrom was dried withoutfurther purification, thereby obtaining 7.2 g (purity of 99.56% byLC-MS) of Intermediate EH14(1).

Synthesis of Compound EH14

7.1 g (18 mmol, 1 eq) of Intermediate EH14(1), 13.2 g (36 mmol, 2 eq) ofCompound I-6, 7.4 g (54 mmol, 3 eq) of potassium carbonate (K₂CO₃), and1.0 g (0.9 mmol, 0.05 eq) of Pd(PPh₃)₄ were added to a mixed solution of50 ml of tetrahydrofuran (THF) and 25 ml of water, and the resultingmixed solution was stirred at a temperature of 85° C. overnight (byusing a pressure reactor). The mixed solution thus obtained was cooledto room temperature, and the reaction mixture was extracted with ethylacetate. The resulting organic layer was dried by using MgSO₄, filtered,and concentrated in vacuum to remove the solvent. A resulting productobtained therefrom was separated and purified by silica gel columnchromatography, thereby obtaining 3.4 g (purity of 99.96% by LC-MS) ofCompound EH14.

LC-Mass Cal.: 559.18 g/mol, Measured.: M+1=560.18 g/mol

Evaluation Example 1 Measurement of Dipole Moment

The electrostatic potential fitting (ESP) charge of each atom ofCompounds EH1, EH2, EH14, and A to C and the distance between atoms wereobtained by using a Density Functional Theory (DFT) method of a Jaguarprogram (that is structurally optimized at a level of B3LYP, 6-31G(d,p), and then, the dipole moment of the relevant compounds. Theresults are shown in Table 1.

TABLE 1 Compound No. Dipole moment (debye) EH1 9.89 EH2 12.66 EH14 11.05A (DPEOP) 8.05 B 5.30 C 3.40

Evaluation Example 2 Evaluation of Maximum Emission Wavelength and Ratioof Delayed Fluorescence Components

(1) Film Preparation

A quartz substrate washed with chloroform and pure water was prepared,and then, Compound EH1 and Compound TD1 were vacuum-(co)-deposited at avolume ratio of 85:15 on the quartz substrate at a vacuum degree of 10⁻⁷torr, thereby preparing a film having a thickness of 50 nm.

(2) Evaluation of Maximum Emission Wavelength

A photoluminescence (PL) spectrum of the film prepared according to thedescription above was measured by using an ISC PC1 spectrofluorometerequipped with a xenon lamp, and based on the PL spectrum, a maximumemission wavelength (peak emission wavelength) of the emission from thefilm was evaluated.

(3) Evaluation of Ratio of Delayed Fluorescence Components

A PL spectrum of the film prepared according to the description abovewas evaluated at room temperature by using a PicoQuant TRPL measurementsystem FluoTime 300 and a PicoQuant pumping source PLS340 (excitationwavelength=340 nm, spectral width=20 nm), a wavelength of a main peak ofthe spectrum was determined, and PLS340 repeatedly measured the numberof photons emitted from the film at the wavelength of the main peak dueto a photon pulse (pulse width=500 ps) applied to the film according totime based on time-correlated single photon counting (TCSPC), therebyobtaining a sufficiently fittable TRPL curve. T_(decay)(Ex) (decay time)of the film was obtained by fitting two or more exponential decayfunctions to the result obtained therefrom. The function used forfitting is expressed by Equation 1, and the greatest value of T_(decay)obtained from each exponential decay function used for fitting was takenas T_(decay)(Ex), whereas the remaining T_(decay) values were used todetermine the lifetime of the decay of normal fluorescence. At thistime, a baseline or background signal curve was obtained by repeatingthe same measurement once more for the same measurement time as themeasurement time for obtaining the TRPL curve in a dark state (a statein which a pumping signal applied to the predetermined film wasblocked), and the baseline or background signal curve was used forfitting as a baseline.

Next, by calculating the ratio of the integral value of the totalluminescence intensity of time to the value obtained by integrating theexponential decay curve (intensity change with time) determined byT_(decay)(Ex) over time, the ratio of delayed fluorescence components tothe total luminescence components was evaluated.

$\begin{matrix}{{f(t)} = {\sum\limits_{i = 1}^{n}{A_{i}\; {\exp ( {{- t}/T_{{decay},i}} )}}}} & {{Equation}\mspace{14mu} 1}\end{matrix}$

(4) Compilation of Table 2

Compounds listed in Table 2 were used in a volume ratio of 85:15 in thefilm preparation according to step (1) to form a film. Then, steps (2)and (3) were repeated to evaluate the maximum emission wavelength ofeach film and the ratio of the delayed fluorescence components, and theresults are summarized in Table 2.

TABLE 2 Ratio of delayed Maximum emission fluorescence componentswavelength (λ_(max)) to total luminescence Film composition (nm)components (%) EH1:TD1 465 65.3 EH2:TD1 467 37.8 EH14:TD1 475 61.3 A(DPEOP):TD1 470 58.8 B:TD1 457 10.3 C:TD1 460 10.4 EH1:TD2 450 22.8EH2:TD2 452 14.0 A (DPEOP):TD2 459 81.3 B:TD2 447 6.1 C:TD2 445 2.5

Referring to Table 2, it was confirmed that the films each includingCompounds EH1, EH2, and EH14 had a higher ratio of delayed fluorescencecomponents to total luminescence components than the films eachincluding Compounds A and B.

Example 1-1

A glass substrate on which an indium tin oxide (ITO) electrode (alsoreferred to as a first electrode or an anode) was formed to a thicknessof 1,500 Å was washed by using distilled water and ultrasonic waves.When the washing with distilled water was completed, sonificationwashing was performed using a solvent, such as isopropyl alcohol,acetone, or methanol. The washed substrate was dried and thentransferred to a plasma washer, and the resultant substrate was washedwith oxygen plasma for 5 minutes and then, transferred to a vacuumdepositing device.

Compound HT3 and Compound HT-D2 were co-deposited on the ITO electrodeon the glass substrate to form a hole injection layer having a thicknessof 100 Å. Then, Compound HT3 was deposited on the hole injection layerto form a hole transport layer having a thickness of 1,350 Å, and mCPwas deposited on the hole transport layer to form an electron blockinglayer having a thickness of 100 Å, thereby forming a hole transportregion.

The host and the delayed fluorescence emitter were co-deposited at avolume ratio of 85:15 on the hole transport region to form an emissionlayer having a thickness of 300 Å. The configurations of the host andthe delayed fluorescence emitter are provided in Table 3.

Compound BCP was vacuum-deposited on the emission layer to form a holeblocking layer having a thickness of 100 Å, Compound ET3 and Liq werevacuum deposited together on the hole blocking layer to form an electrontransport layer having a thickness of 300 Å, and then, Liq was depositedon the electron transport layer to form an electron injection layerhaving a thickness of 10 Å, and an AI second electrode (cathode) havinga thickness of 1,000 Å was formed on the electron injection layer tocomplete the manufacturing of an organic light-emitting device.

Examples 1-1 to 1-3, Comparative Examples 1-A to 1-D, Examples 2-1 and2-2, Comparative Example 2-A to 2-C, Example 3-1, and ComparativeExample 3-C

Organic light-emitting devices were manufactured in the same manner asin Example 1-1, except that the configuration of the emission layer waschanged to the configurations provided in Tables 3 to 6.

Evaluation Example 3 Evaluation of Data About Organic Light-EmittingDevices

For each of the organic light-emitting devices of Examples 1-1 to 1-3,Comparative Examples 1-A to 1-D, Examples 2-1 and 2-2, ComparativeExamples 2-A to 2-C, Example 3-1, and Comparative Example 3-C, CIEycoordinates, an external quantum efficiency (EQE) at 500 cd/m², amaximum emission wavelength (λ_(max), nm), and/or a lifespan (T₈₀) weremeasured by using a current-voltage meter (KEITHLEY 2400) and aluminance meter (MINOLTA Cs-1000A), and the results are summarized inTables 3 to 6. Here, the lifespan (T₈₀, at 500cd/m²) data indicate anamount of time (hr) that lapsed when luminance was 80% of initialluminance (100%).

TABLE 3 EQE Maximum Lifespan at emission (T₈₀) at Delayed 500 wavelength500 fluorescence cd/m² (λ_(max)) cd/m² No. Host emitter CIEy (%) (nm)(hr) Example 1-1 EH1 TD1 0.272 8.0 470 12.55 Example 1-2 EH2 TD1 0.3108.9 475 11.46 Comparative A TD1 0.294 9.7 475 0.13 Example 1-AComparative B TD1 0.179 6.0 453 7.27 Example 1-B Comparative D TD1 0.2548.8 466 7.83 Example 1-D

TABLE 4 Maximum emission Delayed EQE at wavelength fluorescence 500cd/m² (λ_(max)) No. Host emitter CIEy (%) (nm) Example 1-3 EH14 TD10.348 11.1 484 Comparative C TD1 0.231 7.3 461 Example 1-C

TABLE 5 Maximum Lifespan EQE at emission (T₈₀) at Delayed 500 wavelength500 fluorescence cd/m² (λ_(max)) cd/m² No. Host emitter CIEy (%) (nm)(hr) Example 2-1 EH1 TD2 0.195 3.9 448 3.25 Example 2-2 EH2 TD2 0.2133.7 454 1.93 Comparative A TD2 0.230 5.7 458 0.10 Example 2-AComparative B TD2 0.117 3.8 452 1.03 Example 2-B Comparative C TD2 0.1312.9 444 1.45 Example 2-C

TABLE 6 Host Volume ratio of first EQE Maximum Lifespan material atemission (T₈₀) and Delayed 500 wavelength at 500 First Second secondfluorescence cd/m² (λ_(max)) cd/m² No. material material materialemitter CIEy (%) (nm) (hr) Example 3-1 H19 EH14 1:9 TD1 0.340 10.4 48028.60 Comparative H19 C 1:9 TD1 0.235 7.0 461 20.94 Example 3-C

Accordingly, 1) referring to Table 3, it was confirmed that the organiclight-emitting devices of Examples 1-1 and 1-2 had improved lifespancompared to the organic light-emitting devices of Comparative Examples1-A and 1-D, and had improved EQEs and lifespans compared to the organiclight-emitting device of Comparative Example 1-B;

2) referring to Table 4, it was confirmed that the organiclight-emitting device of Example 1-3 had a better EQE than the organiclight-emitting device of Comparative Example 1-C;

3) referring to Table 5, it was confirmed that the organiclight-emitting devices of Examples 2-1 and 2-2 had better lifespans thanthe organic light-emitting devices of Comparative Examples 2-A and 2-B,and had improved EQEs and lifespans than the organic light-emittingdevice of Comparative Example 2-C; and

4) referring to Table 6, it was confirmed that the organiclight-emitting device of Example 3-1 had an improved EQE and lifespanthan the organic light-emitting device of Comparative Example 3-C.

Here, as shown in Table 2, the ratio of the delayed fluorescencecomponents to the total luminescence components (in film) in Compound Awas high. In this regard, as shown in Tables 3 to 5, the organiclight-emitting devices of Comparative Examples 1-A and 2-A eachincluding Compound A was found to have poor lifespan data, whereas theorganic light-emitting devices of Examples 1-1 to 1-3, 2-1, 2-2, and 3-1each emitted delayed fluorescence with a high efficiency and alsosimultaneously had a long lifespan.

According to the one or more embodiments, the organic light-emittingdevice may emit delayed fluorescence with a high efficiency and alsosimultaneously have a long lifespan.

It should be understood that embodiments described herein should beconsidered in a descriptive sense only and not for purposes oflimitation. Descriptions of features or aspects within each embodimentshould typically be considered as available for other similar featuresor aspects in other embodiments.

While one or more embodiments have been described with reference to thefigures, it will be understood by those of ordinary skill in the artthat various changes in form and details may be made therein withoutdeparting from the spirit and scope as defined by the following claims.

What is claimed is:
 1. An organic light-emitting device comprising: afirst electrode; a second electrode facing the first electrode; and anemission layer disposed between the first electrode and the secondelectrode, wherein the emission layer comprises a host and a thermallyactivated delayed fluorescence emitter, and the host comprises acompound represented by Formula 1, a compound represented by Formula 2,or a combination thereof:

wherein, in Formulae 1 and 2, Z₁ to Z₆ are each independently: hydrogen,deuterium, —F, —Cl, —Br, —I, or a cyano group; or a C₁-C₂₀ alkyl group,a phenyl group, a biphenyl group, a terphenyl group, a dibenzofuranylgroup, or a dibenzothiophenyl group, each unsubstituted or substitutedwith deuterium, —F, —Cl, —Br, —I, a cyano group, a C₁-C₂₀ alkyl group, aphenyl group, a biphenyl group, or any combination thereof, b1 to b6 areeach independently 1, 2, 3, or 4, and in Formulae 1 and 2, at least oneof, i) Z₁ in the number of b1, ii) Z₂ in the number of b2, iii) Z₃ inthe number of b3, iv) Z₄ in the number of b4, v) Z₅ in the number of b5,and vi) R₆ in the number of b6 is a cyano group.
 2. The organiclight-emitting device of claim 1, wherein Z₁ to Z₆ are eachindependently: hydrogen, deuterium, or a cyano group; or a C₁-C₁₀ alkylgroup, a phenyl group, a biphenyl group, a terphenyl group, adibenzofuranyl group, or a dibenzothiophenyl group, each unsubstitutedor substituted with deuterium, a cyano group, a C₁-C₁₀ alkyl group, aphenyl group, a biphenyl group, or any combination thereof, and b1 to b6are each independently 0, 1, or
 2. 3. The organic light-emitting deviceof claim 1, wherein the number of a cyano group included in the compoundrepresented by Formula 1 and the number of a cyano group included in thecompound represented by Formula 2 are each independently 1, 2, 3, or 4.4. The organic light-emitting device of claim 1, wherein in Formulae 1and 2, at least one of, i) Z₁ in the number of b1 and ii) Z₂ in thenumber of b2 is a cyano group, at least one of, i) Z₃ in the number ofb3 and ii) Z₄ in the number of b4 is a cyano group, at least one of, i)Z₅ in the number of b5 and ii) Z₆ in the number of b6 is a cyano group,at least one of, i) Z₁ in the number of b1 and ii) Z₂ in the number ofb2 is a cyano group, and at least one of, i) Z₃ in the number of b3 andii) Z₄ in the number of b4 is a cyano group, at least one of, i) Z₁ inthe number of b1 and ii) Z₂ in the number of b2 is a cyano group, and atleast one of, i) Z₅ in the number of b5 and ii) Z₆ in the number of b6is a cyano group, at least one of, i) Z₃ in the number of b3 and ii) Z₄in the number of b4 is a cyano group, and at least one of, i) Z₅ in thenumber of b5 and ii) Z₆ in the number of b6 is a cyano group, or atleast one of, i) Z₁ in the number of b1 and ii) Z₂ in the number of b2is a cyano group, at least one of, i) Z₃ in the number of b3 and ii) Z₄in the number of b4 is a cyano group, and at least one of, i) Z₅ in thenumber of b5 and ii) Z₆ in the number of b6 is a cyano group.
 5. Theorganic light-emitting device of claim 1, wherein a group represented by

in Formula 1 is a group represented by one of Formulae PO1 to PO25, agroup represented by

in Formula 2 is a group represented by one of Formulae PM1 to PM25:

wherein, in Formulae PO1 to PO25 and PM1 to PM25, Z₁₀ to Z₁₉ are eachindependently: hydrogen, deuterium, —F, —Cl, —Br, —I, or a cyano group;or a C₁-C₂₀ alkyl group, a phenyl group, a biphenyl group, a terphenylgroup, a dibenzofuranyl group, or a dibenzothiophenyl group, eachunsubstituted or substituted with deuterium, —F, —Cl, —Br, —I, a cyanogroup, a C₁-C₂₀ alkyl group, a phenyl group, a biphenyl group, or anycombination thereof, and * and *′ each indicate a binding site to aneighboring nitrogen atom.
 6. The organic light-emitting device of claim1, wherein a group represented by

in Formulae 1 and 2 is a group represented by one of Formulae A1-1 toA1-3, a group represented by

in Formulae 1 and 2 is a group represented by one of Formulae A2-1 toA2-3:

wherein, in Formulae A1-1 to A1-3 and A2-1 to A2-3, Z₂₁ to Z₂₈ and Z₃₁to Z₃₈ are each independently: hydrogen, deuterium, —F, —Cl, —Br, —I, ora cyano group; or a C₁-C₂₀ alkyl group, a phenyl group, a biphenylgroup, a terphenyl group, a dibenzofuranyl group, or a dibenzothiophenylgroup, each unsubstituted or substituted with deuterium, —F, —Cl, —Br,—I, a cyano group, a C₁-C₂₀ alkyl group, a phenyl group, a biphenylgroup, or any combination thereof, and * and *′ each indicate a bindingsite to a neighboring atom.
 7. The organic light-emitting device ofclaim 1, wherein the host comprises at least one of Compounds EH1 toEH15:


8. The organic light-emitting device of claim 1, wherein the compoundrepresented by Formula 1 and the compound represented by Formula 2 eachhave a dipole moment of about 6.4 debye or more.
 9. The organiclight-emitting device of claim 1, wherein a difference between a tripletenergy level of the thermally activated delayed fluorescence emitter anda singlet energy level of the thermally activated delayed fluorescenceemitter is greater than or equal to about 0 eV to less than or equal toabout 0.5 eV, and the triplet energy level and the singlet energy levelare each evaluated by using a density functional theory method of aGaussian program that is structurally optimized at a level ofB3LYP/6-31G(d,p).
 10. The organic light-emitting device of claim 1,wherein the thermally activated delayed fluorescence emitter comprises acompound represented by Formula 11:

wherein, in Formula 11, X₁ is a single bond, N-[(L₄)_(c4)-R₄],C(R₅)(R₆), O, or S, A₁ and A₂ are each independently a benzene group, anaphthalene group, an indene group, an indole group, a benzofuran group,a benzothiophene group, a benzosilole group, a fluorene group, acarbazole group, a dibenzofuran group, a dibenzothiophene group, or adibenzosilole group, L₃ and L₄ are each independently a substituted orunsubstituted C₃-C₁₀ cycloalkylene group, a substituted or unsubstitutedC₂-C₁₀ heterocycloalkylene group, a substituted or unsubstituted C₃-C₁₀cycloalkenylene group, a substituted or unsubstituted C₂-C₁₀heterocycloalkenylene group, a substituted or unsubstituted C₆-C₆₀arylene group, a substituted or unsubstituted C₁-C₆₀ heteroarylenegroup, a substituted or unsubstituted divalent non-aromatic condensedpolycyclic group, or a substituted or unsubstituted divalentnon-aromatic condensed heteropolycyclic group, c3 and c4 are eachindependently an integer from 0 to 4, R₁ to R₅ are each independentlyhydrogen, deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group,a nitro group, an amino group, an amidino group, a hydrazine group, ahydrazone group, a carboxylic acid group or a salt thereof, a sulfonicacid group or a salt thereof, a phosphoric acid group or a salt thereof,a substituted or unsubstituted C₁-C₆₀ alkyl group, a substituted orunsubstituted C₂-C₆₀ alkenyl group, a substituted or unsubstitutedC₂-C₆₀ alkynyl group, a substituted or unsubstituted C₁-C₆₀ alkoxygroup, a substituted or unsubstituted C₃-C₁₀ cycloalkyl group, asubstituted or unsubstituted C₂-C₁₀ heterocycloalkyl group, asubstituted or unsubstituted C₃-C₁₀ cycloalkenyl group, a substituted orunsubstituted C₂-C₁₀ heterocycloalkenyl group, a substituted orunsubstituted C₆-C₆₀ aryl group, a substituted or unsubstituted C₆-C₆₀aryloxy group, a substituted or unsubstituted C₆-C₆₀ arylthio group, asubstituted or unsubstituted C₁-C₆₀ heteroaryl group, a substituted orunsubstituted monovalent non-aromatic condensed polycyclic group, asubstituted or unsubstituted monovalent non-aromatic condensedheteropolycyclic group, —Si(Q₁)(Q₂)(Q₃), —N(Q₄)(Q₅), or —B(Q₆)(Q₇), a1and a2 are each independently an integer from 0 to 10, a substituent ofthe substituted C₃-C₁₀ cycloalkylene group, the substituted C₂-C₁₀heterocycloalkylene group, the substituted C₃-C₁₀ cycloalkenylene group,the substituted C₂-C₁₀ heterocycloalkenylene group, the substitutedC₆-C₆₀ arylene group, the substituted C₁-C₆₀ heteroarylene group, thesubstituted divalent non-aromatic condensed polycyclic group, thesubstituted divalent non-aromatic condensed heteropolycyclic group, thesubstituted C₁-C₆₀ alkyl group, the substituted C₂-C₆₀ alkenyl group,the substituted C₂-C₆₀ alkynyl group, the substituted C₁-C₆₀ alkoxygroup, the substituted C₃-C₁₀ cycloalkyl group, the substituted C₂-C₁₀heterocycloalkyl group, the substituted C₃-C₁₀ cycloalkenyl group, thesubstituted C₂-C₁₀ heterocycloalkenyl group, the substituted C₆-C₆₀ arylgroup, the substituted C₆-C₆₀ aryloxy group, the substituted C₆-C₆₀arylthio group, the substituted C₁-C₆₀ heteroaryl group, the substitutedmonovalent non-aromatic condensed polycyclic group, or the substitutedmonovalent non-aromatic condensed heteropolycyclic group is: deuterium,—F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, anamino group, an amidino group, a hydrazine group, a hydrazone group, acarboxylic acid group or a salt thereof, a sulfonic acid group or a saltthereof, a phosphoric acid group or a salt thereof, a C₁-C₆₀ alkylgroup, a C₂-C₆₀ alkenyl group, a C₂-C₆₀ alkynyl group, a C₁-C₆₀ alkoxygroup, or any combination thereof; a C₁-C₆₀ alkyl group, a C₂-C₆₀alkenyl group, a C₂-C₆₀ alkynyl group, a C₁-C₆₀ alkoxy group, or acombination thereof, each substituted with deuterium, —F, —Cl, —Br, —I,a hydroxyl group, a cyano group, a nitro group, an amino group, anamidino group, a hydrazine group, a hydrazone group, a carboxylic acidgroup or a salt thereof, a sulfonic acid group or a salt thereof, aphosphoric acid group or a salt thereof, a C₃-C₁₀ cycloalkyl group, aC₂-C₁₀ heterocycloalkyl group, a C₃-C₁₀ cycloalkenyl group, a C₂-C₁₀heterocycloalkenyl group, a C₆-C₆₀ aryl group, a C₆-C₆₀ aryloxy group, aC₆-C₆₀ arylthio group, a C₁-C₆₀ heteroaryl group, a monovalentnon-aromatic condensed polycyclic group, a monovalent non-aromaticcondensed heteropolycyclic group, —Si(Q₁₁)(Q₁₂)(Q₁₃), —N(Q₁₄)(Q₁₅),—B(Q₁₆)(Q₁₇), or any combination thereof; a C₃-C₁₀ cycloalkyl group, aC₁-C₁₀ heterocycloalkyl group, a C₃-C₁₀ cycloalkenyl group, a C₂-C₁₀heterocycloalkenyl group, a C₆-C₆₀ aryl group, a C₆-C₆₀ aryloxy group, aC₆-C₆₀ arylthio group, a C₁-C₆₀ heteroaryl group, a monovalentnon-aromatic condensed polycyclic group, a monovalent non-aromaticcondensed heteropolycyclic group, or any combination thereof; a C₃-C₁₀cycloalkyl group, a C₂-C₁₀ heterocycloalkyl group, a C₃-C₁₀ cycloalkenylgroup, a C₂-C₁₀ heterocycloalkenyl group, a C₆-C₆₀ aryl group, a C₆-C₆₀aryloxy group, a C₆-C₆₀ arylthio group, a C₁-C₆₀ heteroaryl group, amonovalent non-aromatic condensed polycyclic group, or a monovalentnon-aromatic condensed heteropolycyclic group, each substituted withdeuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitrogroup, an amino group, an amidino group, a hydrazine group, a hydrazonegroup, a carboxylic acid group or a salt thereof, a sulfonic acid groupor a salt thereof, a phosphoric acid group or a salt thereof, a C₁-C₆₀alkyl group, a C₂-C₆₀ alkenyl group, a C₂-C₆₀ alkynyl group, a C₁-C₆₀alkoxy group, a C₃-C₁₀ cycloalkyl group, a C₂-C₁₀ heterocycloalkylgroup, a C₃-C₁₀ cycloalkenyl group, a C₂-C₁₀ heterocycloalkenyl group, aC₆-C₆₀ aryl group, a C₆-C₆₀ aryloxy group, a C₆-C₆₀ arylthio group, aC₁-C₆₀ heteroaryl group, a monovalent non-aromatic condensed polycyclicgroup, a monovalent non-aromatic condensed heteropolycyclic group,—Si(Q₂₁)(Q₂₂)(Q₂₃), —N(Q₂₄)(Q₂₅), —B(Q₂₆)(Q₂₇), or any combinationthereof; —Si(Q₃₁)(Q₃₂)(Q₃₃), —N(Q₃₄)(Q₃₅), —B(Q₃₆)(Q₃₇), or acombination thereof, and Q₁ to Q₇, Q₁₁ to Q₁₇, Q₂₁ to Q₂₇, and Q₃₁ toQ₃₇ are each independently hydrogen, a substituted or unsubstitutedC₁-C₆₀ alkyl group, a substituted or unsubstituted C₂-C₆₀ alkenyl group,a substituted or unsubstituted C₂-C₆₀ alkynyl group, a substituted orunsubstituted C₁-C₆₀ alkoxy group, a substituted or unsubstituted C₃-C₁₀cycloalkyl group, a substituted or unsubstituted C₂-C₁₀ heterocycloalkylgroup, a substituted or unsubstituted C₃-C₁₀ cycloalkenyl group, asubstituted or unsubstituted C₂-C₁₀ heterocycloalkenyl group, asubstituted or unsubstituted C₆-C₆₀ aryl group, a substituted orunsubstituted C₆-C₆₀ aryloxy group, a substituted or unsubstitutedC₆-C₆₀ arylthio group, a substituted or unsubstituted C₁-C₆₀ heteroarylgroup, a substituted or unsubstituted monovalent non-aromatic condensedpolycyclic group, or a substituted or unsubstituted monovalentnon-aromatic condensed heteropolycyclic group.
 11. The organiclight-emitting device of claim 10, wherein R₃ comprises at least one πelectron-depleted nitrogen-containing cyclic group.
 12. The organiclight-emitting device of claim 10, wherein R₃ is: a group represented byFormula 13(1) or a group represented by Formula 13(2); a phenyl group, abiphenyl group, a terphenyl group, a naphthyl group, a fluorenyl group,a quinolinyl group, an isoquinolinyl group, a carbazolyl group, adibenzofuranyl group, a dibenzothiophenyl group, or an indolocarbazolylgroup; or a phenyl group, a biphenyl group, a terphenyl group, anaphthyl group, a fluorenyl group, a quinolinyl group, an isoquinolinylgroup, a carbazolyl group, a dibenzofuranyl group, a dibenzothiophenylgroup, or an indolocarbazolyl group, each substituted with deuterium, aC₁-C₁₀ alkyl group, a C₁-C₁₀ alkoxy group, a phenyl group, a biphenylgroup, a terphenyl group, a naphthyl group, a fluorenyl group, apyridinyl group, a pyrimidinyl group, a pyrazinyl group, a pyridazinylgroup, a triazinyl group, a quinolinyl group, an isoquinolinyl group, acarbazolyl group, a dibenzofuranyl group, a dibenzothiophenyl group, anindolocarbazolyl group, —Si(Q₃₁)(Q₃₂)(Q₃₃), or any combination thereof,and Q₃₁ to Q₃₃ are each independently a C₁-C₁₀ alkyl group, a C₁-C₁₀alkoxy group, a phenyl group, a biphenyl group, a terphenyl group, or anaphthyl group:

wherein, in Formulae 13(1) and 13(2), X₁₁ to X₁₅ are each independentlyC or N, wherein at least one of X₁₁ to X₁₅ is N, A₁₁ and A₁₂ are eachindependently a benzene group, a naphthalene group, a pyridine group, apyrazine group, a pyrimidine group, a pyridazine group, a quinolinegroup, an isoquinoline group, a quinoxaline group, or a quinazolinegroup, wherein A₁₁, A₁₂, or a combination thereof is a pyridine group, apyrazine group, a pyrimidine group, a pyridazine group, a quinolinegroup, an isoquinoline group, a quinoxaline group, or a quinazolinegroup, X₁₆ iS N-[(L₁₂)_(a12)-R₁₂], C(R₁₄)(R₁₅), O, or S, X₁₇ is a singlebond, N-[(L₁₃)_(a13)-R₁₃], C(R₁₆)(R₁₇), O, or S, d16 is an integer from0 to 6, d14 is an integer from 0 to 4, and * indicates a binding site toa neighboring atom.
 13. The organic light-emitting device of claim 10,wherein the thermally activated delayed fluorescence emitter comprises acompound represented by one of Formulae 11-1 to 11-7:

wherein, in Formulae 11-1 to 11-7, X₂ is N-[(L₅)_(c5)-R₇], C(R₈)(R₉), O,or S, L₅ and c5 are each independently defined the same as L₃ and c3,respectively, in claim 10, R₇ is defined the same as R₃ in claims 10, R₈and R₉ are each independently defined the same as R₅ and R₆,respectively, in claim 10, a16 is an integer from 0 to 6, and a14 anda24 are each independently an integer from 0 to
 4. 14. The organiclight-emitting device of claim 1, wherein the emission layer does notcomprise a transition metal-containing organometallic compound.
 15. Theorganic light-emitting device of claim 1, wherein the light emitted bythe thermally activated delayed fluorescence emitter in the emissionlayer is blue light.
 16. The organic light-emitting device of claim 1,wherein an amount of the thermally activated delayed fluorescenceemitter is in a range of about 0.01 parts by weight to about 30 parts byweight based on 100 parts by weight of the host.
 17. The organiclight-emitting device of claim 1, wherein the host comprises a firstmaterial and a second material, the first material and the secondmaterial are different from each other, and the second materialcomprises the compound represented by Formula 1, the compoundrepresented by Formula 2, or a combination thereof.
 18. The organiclight-emitting device of claim 17, wherein the first material comprisesat least one π electron-depleted nitrogen-free cyclic group, and doesnot comprise an electron transport moiety.
 19. The organiclight-emitting device of claim 17, wherein the first material comprisesa benzene group not including a cyano group and a carbazole group notincluding a cyano group.
 20. The organic light-emitting device of claim17, wherein the first material comprises a compound represented byFormula H-1(1), a compound represented by Formula H-1(2), a compoundrepresented by Formula H-1(3), or any combination thereof:

wherein, in Formulae H-1(1) to H-1(3), ring A₄₁ to ring A₄₄ are eachindependently a benzene group, a naphthalene group, an indene group, anindole group, a benzofuran group, a benzothiophene group, a benzosilolegroup, a fluorene group, a carbazole group, a dibenzofuran group, adibenzothiophene group, or a dibenzosilole group, X₄₁ isN-[(L₄₁₁)_(c411)-Z₄₁₁], C(Z₄₁₅)(Z₄₁₆), O, or S, X₄₂ is a single bond,N-[(L₄₁₂)_(c412)-Z₄₁₂], C(Z₄₁₇)(Z₄₁₈), O, or S, X₄₃ iSN-[(L₄₁₃)_(c413)-Z₄₁₃], C(Z₄₁₉)(Z₄₂₀), O, or S, X₄₄ is a single bond,N-[(L₄₁₄)_(c414)-Z₄₁₄], C(Z₄₂₁)(Z₄₂₂), O, or S, L₄₀₁ and L₄₁₁ to L₄₁₄are each independently: a single bond; or a π electron-depletednitrogen-free cyclic group unsubstituted or substituted with deuterium,a C₁-C₂₀ alkyl group, a C₁-C₂₀ alkoxy group, a phenyl group, a naphthylgroup, a fluorenyl group, a carbazolyl group, a dibenzofuranyl group, adibenzothiophenyl group, a triphenylenyl group, a biphenyl group, aterphenyl group, a tetraphenyl group, a (C₁-C₂₀ alkyl)phenyl group,—Si(Q₄₀₁)(Q₄₀₂)(Q₄₀₃), or any combination thereof, a401 and c411 to c414are each independently an integer from 1 to 10, wherein, when a401 istwo or more, two or more L₄₀₁ are identical to or different from eachother, when c411 is two or more, two or more L₄₁₁ are identical to ordifferent from each other, when c412 is two or more, two or more L₄₁₂are identical to or different from each other, when c413 is two or more,two or more L₄₁₃ are identical to or different from each other, and whenc414 is two or more, two or more L₄₁₄ are identical to or different fromeach other, Z₄₁ to Z₄₄ and Z₄₁₁ to Z₄₂₂ are each independently:hydrogen, deuterium, a C₁-C₂₀ alkyl group, or a C₁-C₂₀ alkoxy group; ora π electron-depleted nitrogen-free cyclic group unsubstituted orsubstituted with deuterium, a C₁-C₂₀ alkyl group, a C₁-C₂₀ alkoxy group,a phenyl group, a naphthyl group, a fluorenyl group, a carbazolyl group,a dibenzofuranyl group, a dibenzothiophenyl group, a triphenylenylgroup, a biphenyl group, a terphenyl group, a tetraphenyl group, a(C₁-C₂₀ alkyl)phenyl group, —Si(Q₄₀₁)(Q₄₀₂)(Q₄₀₃), or any combinationthereof, b41 to b44 are each independently 1, 2, 3, or 4, and Q₄₀₁ toQ₄₀₃ are each independently hydrogen, deuterium, a C₁-C₂₀ alkyl group, aC₁-C₂₀ alkoxy group, a phenyl group, a naphthyl group, a fluorenylgroup, a carbazolyl group, a dibenzofuranyl group, a dibenzothiophenylgroup, a triphenylenyl group, a biphenyl group, a terphenyl group, or atetraphenyl group.